The correct service to identify similar faces in a set of images is Azure AI Vision, which includes the Face API capability. According to the Microsoft Learn module "Analyze images with Azure AI Vision", this service provides prebuilt models for face detection, facial recognition, and similarity matching.
The Face API can detect individual faces in images and extract unique facial features to create a face embedding (a numerical representation of the face). It then compares these embeddings across multiple images to determine whether faces are similar or belong to the same person. This functionality is commonly used in identity verification, photo management systems, and security solutions.
The other options are incorrect:
* B. Azure AI Custom Vision is used for custom image classification or object detection but does not provide face similarity or recognition features.
* C. Azure AI Language processes text-based data (sentiment, entities, key phrases) - not visual content.
* D. Azure OpenAI Service focuses on text generation, summarization, and conversation, not facial analysis.
Therefore, the Microsoft-verified service for identifying similar faces across images is A. Azure AI Vision.

Explanation:

According to the Microsoft Azure AI Fundamentals (AI-900) official study materials and Microsoft Learn documentation on GitHub Copilot, the GitHub Copilot extension for Microsoft Visual Studio Code (VS Code) is powered by the OpenAI Codex model, a specialized descendant of the GPT (Generative Pre-trained Transformer) family of models. The OpenAI Codex model is specifically fine-tuned for programming tasks- it understands and generates code in multiple programming languages such as Python, JavaScript, C#, and more.
GitHub Copilot functions as an AI-powered coding assistant that suggests complete lines or blocks of code, helps write comments, and can even generate functions based on natural language prompts entered by the developer. When a user types a comment like "// sort a list of numbers in ascending order," Copilot uses the Codex model to understand the intent and generate an appropriate code implementation.
The integration with Visual Studio Code allows developers to work efficiently without needing to switch between documentation and their coding environment. GitHub Copilot leverages context-aware suggestions, meaning it understands the surrounding code, function definitions, and variable names to provide relevant completions.
The other options are incorrect because:
* GitHub source control manages code repositories but doesn't use AI models.
* IntelliSense is a built-in VS Code feature for code completion but doesn't rely on OpenAI models.
* Microsoft 365 Copilot uses large language models (like GPT-4) for productivity tools such as Word, Excel, and Outlook-not for code generation.
Therefore, the correct choice that uses the OpenAI Codex model in Visual Studio Code is GitHub Copilot, aligning with Microsoft's AI-900 learning objectives under "Identify common use cases for Azure OpenAI and GitHub Copilot."

According to the Microsoft Azure AI Fundamentals (AI-900) official study guide and Microsoft Learn modules on machine learning concepts, ensuring that the accuracy of a predictive model can be proven requires data partitioning-specifically splitting the available data into training and testing datasets. This is a foundational concept in supervised machine learning.
When you split the data, typically about 70-80% of the dataset is used for training the model, while the remaining 20-30% is used for testing (or validation). The reason behind this approach is to ensure that the model's performance metrics-such as accuracy, precision, recall, and F1-score-are evaluated on data the model has never seen before. This prevents overfitting and allows you to demonstrate that the model generalizes well to new, unseen data.
In the AI-900 Microsoft Learn content under "Describe the machine learning process", it is explained that after cleaning and transforming the data, the next essential step is data splitting to "evaluate model performance objectively." By keeping training and testing data separate, you can prove the reliability and accuracy of the model's predictions, which is particularly crucial in sensitive domains like clinical or healthcare analytics, where decision transparency and validation are vital.
* Option A (Train the model by using the clinical data) is incorrect because you should not train and evaluate on the same data-it would lead to biased results.
* Option C (Train the model using automated ML) is incorrect because automated ML is a method for training and tuning, but it doesn't inherently prove accuracy.
* Option D (Validate the model by using the clinical data) is also incorrect if you use the same dataset for validation and training-it would not prove true accuracy.
Therefore, per Microsoft's official AI-900 study content, the verified correct answer is B. Split the clinical data into two datasets.

A transformer model is the foundational architecture behind many modern natural language processing systems such as GPT and BERT. It processes text data through multiple key stages. According to the Microsoft Azure AI Fundamentals (AI-900) curriculum and Microsoft Learn materials, the major stages of a transformer-based large language model are tokenization, embedding calculation, and next token prediction.
* Tokenization (C) - The first step converts raw text into smaller units called tokens (words, subwords, or characters). This process allows the model to handle text in a structured numerical form rather than as raw language.
* Embedding Calculation (B) - After tokenization, the tokens are mapped into high-dimensional numeric vectors, known as embeddings. These embeddings capture semantic relationships between words and phrases so that the model can understand context and meaning.
* Next Token Prediction (D) - This stage is the heart of transformer operation, where the model predicts the next likely token in a sequence based on prior tokens. Repeated next-token predictions enable text generation, summarization, or translation.
Options A (object detection) and E (anonymization) are incorrect because they relate to vision and privacy workflows, not language modeling.

Extracting relationships and insights from large volumes of unstructured data (such as documents, text files, or images) aligns with the Knowledge Mining workload in Microsoft Azure AI. According to the Microsoft AI Fundamentals (AI-900) study guide and Microsoft Learn module "Describe features of common AI workloads," knowledge mining involves using AI to search, extract, and structure information from vast amounts of unstructured or semi-structured content.
In a typical knowledge mining solution, tools like Azure AI Search and Azure AI Document Intelligence work together to index data, apply cognitive skills (such as OCR, key phrase extraction, and entity recognition), and then enable users to discover relationships and patterns through intelligent search. The process transforms raw content into searchable knowledge.
The key characteristics of knowledge mining include:
* Using AI to extract entities and relationships between data points.
* Applying cognitive skills to text, images, and documents.
* Creating searchable knowledge stores from unstructured data.
Hence, B. Knowledge Mining is correct.
The other options-computer vision, NLP, and anomaly detection-deal with image recognition, language understanding, and data irregularities, respectively, not large-scale information extraction.