Explanation
Plug-ins can be used declaratively in all of the following components in APEX: Dynamic Actions, Regions, Items, Process Type, and Authentication and Authorization Schemes. Plug-ins are shared components that enable developers to extend the native functionality of APEX with custom components1. Plug-ins can be created or imported from the Shared Components page or the App Gallery1.

Explanation
Low Code Apps are applications that are developed using a low-code development platform such as Oracle APEX. Low Code Apps have the following characteristics:
Scalable: Low Code Apps can handle large volumes of data and users without compromising performance or reliability. They can also leverage the scalability features of the underlying database or cloud platform.
Provide Rich Functionality with Less Code: Low Code Apps can provide complex business logic, user interface, security, and integration features with minimal or no coding. They use declarative tools, visual editors, drag-and-drop components, and pre-built templates to speed up the development process.
The other options are incorrect because:
Not Mobile Friendly: Low Code Apps are mobile friendly by default. They use responsive design techniques to adapt to different screen sizes and orientations. They also support touch gestures, device features, and offline capabilities.
Expensive: Low Code Apps are not expensive to develop or maintain. They reduce the cost of development by requiring less time, resources, and skills. They also reduce the cost of maintenance by simplifying the deployment, testing, and debugging processes.
Verified References: [What is Low Code?] [Why Choose Oracle APEX?]

Explanation
The APEX_MAIL package is an API for the APEX mail system that enables developers to send emails from PL/SQL code. Some of the statements that are true about the APEX_MAIL package are:
You can add files as attachments to your emails using the APEX_MAIL package. You can use the APEX_MAIL.ADD_ATTACHMENT procedure to add one or more files as attachments to your emails.
The files can be in various formats, such as PDF, DOCX, XLSX, etc.
You can send emails using the APEX_MAIL package from an Oracle APEX application. You can use the APEX_MAIL.SEND procedure or function to send an outbound email message from your application. You can also specify various parameters for your email, such as sender, recipients, subject, body, priority, etc. The APEX_MAIL package does not support sending emails only to Oracle database users or receiving emails in an Oracle APEX application. You can send emails to any valid email address or use other tools or services to receive emails. Verified References: [APEX_MAIL - Oracle Help Center], [APEX_MAIL : Send Emails from PL/SQL - ORACLE-BASE]

Explanation
The feature pages that can be created using the Create Page Wizard are About Page, Access Control, Activity Reporting, Configuration Options, Email Reporting, Feedback, Login Page, and Theme Style Selection. These pages provide application-level functionality that can be added to an existing application. Search Page and Unified Task List are not feature pages that can be created using the Create Page Wizard. Verified References: Managing Feature PagesFeature Page Types

Explanation
Search Configurations is a feature that allows developers to define how end users can search for data in an application. There are three types of search configurations: Standard, List, and Oracle Text. Oracle Text is a search type that provides linguistic and fuzzy search capabilities by using an Oracle Text index on a table column or view column. Linguistic search enables end users to search for data based on language-specific rules and preferences, such as stemming, stopwords, synonyms, etc. Fuzzy search enables end users to search for data based on approximate matches that account for spelling errors, typos, OCR errors, etc. Verified References: [Managing Search Configurations - Oracle Help Center], [Oracle Text User's Guide]