The correct answer is C. SQL injection. According to CompTIA DataSys+ objectives, web-based input mechanisms such as contact forms and online surveys represent a significant attack surface for databases if they are not properly secured. These forms commonly accept user-supplied input that is later processed by backend database queries. If input validation and parameterized queries are not correctly implemented, attackers can exploit this by injecting malicious SQL code into form fields.
SQL injection attacks allow an attacker to manipulate database queries executed by the application. This can result in unauthorized access to sensitive data, data modification, data deletion, or even full database compromise. In a healthcare environment, this risk is especially critical because patient data is highly sensitive and often protected by regulatory requirements. DataSys+ highlights SQL injection as one of the most common and dangerous database-focused attacks due to its direct impact on data confidentiality, integrity, and availability.
Option A, Denial of Service (DoS), primarily affects system availability by overwhelming resources, but it does not directly target data stored within the database. Option B, ransomware, typically requires malware execution on servers or endpoints and is not specifically tied to web form input mechanisms. Option D, brute- force attacks, focus on repeatedly guessing authentication credentials and are more closely associated with login systems rather than data entry forms or surveys.
CompTIA DataSys+ materials emphasize that databases connected to web applications must use strong input validation, stored procedures, prepared statements, and least-privilege database accounts to mitigate SQL injection risks. Because contact forms and surveys directly interact with database queries and rely on untrusted user input, SQL injection represents the most direct and realistic threat in this scenario.
Therefore, SQL injection is the attack type to which the company's data is most vulnerable, making option C the verified and correct answer.

The characteristic of all non-relational databases is unstructured data. Unstructured data is data that does not have a predefined or fixed format, schema, or structure. Unstructured data can include various types of data, such as text, images, audio, video, etc. Non-relational databases, also known as NoSQL databases, are databases that store and manage unstructured data using different models, such as key-value, document, graph, columnar, etc. Non-relational databases are suitable for handling large volumes, variety, and velocity of data that do not fit well in the relational model. The other options are either characteristics of relational databases or not related to database types at all. For example, columns with the same data type, logical record groupings, and tabular schema are characteristics of relational databases, which are databases that store and manage structured data using tables, rows, columns, and constraints. References: CompTIA DataSys+ Course Outline, Domain 1.0 Database Fundamentals, Objective 1.1 Given a scenario, identify common database types.

The best suited database engine for this task is MongoDB. MongoDB is a type of non-relational database that stores data as documents in JSON-like format. MongoDB allows administrators to perform quick and simple queries on unstructured data, such as text, images, videos, or social media posts, without requiring a predefined schema or complex joins. MongoDB also supports cloud-based deployment, scalability, and high availability. The other options are either relational databases that require a fixed schema and structure for data, or specialized databases that are designed for specific purposes, such as graph databases for storing and analyzing network data. References: CompTIA DataSys+ Course Outline, Domain 1.0 Database Fundamentals, Objective 1.1 Given a scenario, identify and apply database structure types.

The correct answer is A. Columnstore. According to CompTIA DataSys+, a columnstore index stores data in a column-oriented, tabular structure, where each column of a table is stored separately rather than storing entire rows together. This design is particularly optimized for analytical and reporting workloads, which commonly scan large datasets and perform aggregations on specific columns.
In a columnstore index, data is logically still represented in a table-like (tabular) format, but physically organized by columns instead of rows. This allows the database engine to read only the required columns for a query, significantly reducing disk I/O and improving query performance. DataSys+ highlights columnstore indexes as a best practice for data warehousing, business intelligence, and read-heavy analytical queries.
Option B, a non-clustered index, stores a separate index structure that contains indexed column values and pointers to the underlying table rows. While it improves lookup performance, it does not store data in a tabular columnar format. Option C, a unique index, is a constraint-based index that enforces uniqueness on column values but does not define how data is physically stored. Option D, a secondary index, is a general term for indexes that are not primary and does not specifically describe column-based tabular storage.
Sys+ emphasizes understanding different index types and their appropriate use cases. Columnstore indexes are distinct because they physically reorganize data by columns, compress data efficiently, and support high-performance analytics. This makes them especially effective in scenarios involving large datasets and complex queries.
Therefore, the index type that stores records in a tabular, column-oriented format is the columnstore index
, making option A the correct and fully verified answer aligned with CompTIA DataSys+ objectives.

The SQL syntax that the administrator should use to create an object is option B. This syntax uses the CREATE TABLE statement to define a new table named customer with four columns: customer_id, name, email, and phone. Each column has a data type and a constraint, such as NOT NULL or PRIMARY KEY. The other options either have syntax errors, use incorrect keywords, or do not specify the table name or columns correctly. References: CompTIA DataSys+ Course Outline, Domain 1.0 Database Fundamentals, Objective 1.1 Given a scenario, identify and apply database structure types.