Explanation
An interactive grid is a customizable report that allows end users to modify the data and layout of the report.
To make an employee's commission editable in the grid, you need to perform two actions:
In the Interactive Grid attributes, turn "On" the Enabled switch, under the Edit group. This enables editing for the entire interactive grid region and allows you to specify which columns are editable and which are not.
Ensure that the "Primary Key" switch is turned "On" for the EMPNO column. This identifies the EMPNO column as the primary key for the EMP table and allows APEX to perform DML operations on the table when end users edit the data in the grid. You do not need to set EMPNO or ENAME to
"Display Only" or select COMM for "Allowed Row Operations Column" to make an employee's commission editable in the grid. Verified References: [Managing Interactive Grids - Oracle Help Center], [Interactive Grid Attributes - Oracle Help Center]

Explanation
A REST Data Source with ORDS as the REST Data Source Type is based on an AutoREST-enabled table or view on a remote Oracle Database. AutoREST enables you to perform CRUD (Create, Read, Update, Delete) operations on a table or view using standard HTTP methods. When a user updates an employee record in an editable interactive grid that uses this REST Data Source as source, the PUT operation defined in the REST Data Source is utilized to update a record in the EMP table on the remote Oracle Database. The PUT operation sends an HTTP PUT request to the REST endpoint with the primary key value of the record and the updated column values in JSON format. Verified References: Creating REST Data Sources - Oracle Help Center, Oracle REST Data Services (ORDS) : AutoREST - Oracle-Base

Explanation
When a table or a SQL query returns many rows, an interactive grid is best displayed to the user with pagination. Pagination enables users to navigate through large data sets by displaying a subset of data at a time3. The two types of pagination available for interactive grids are Page and Scroll3. Page pagination displays a fixed number of rows per page and provides controls to navigate between pages. Scroll pagination displays rows as the user scrolls down the grid and fetches more data as needed

Explanation
When you use the Create Page Wizard to create a faceted search page on any table or SQL query, such as EMP table, APEX generates a classic report region as default report type for this page. A classic report region displays data from a SQL query or PL/SQL function returning a SQL query in tabular format. A faceted search page also contains a region of Faceted Search type, which holds one or more facets that allow end users to filter data by applying one or more facets. Verified References: Creating Faceted Search Pages - Oracle Help Center, Creating Classic Reports - Oracle Help Center

Explanation
Using the App Builder component, you can perform the following tasks:
Edit pages in the page designer: You can use the Page Designer tool to modify the pages in your application using drag-and-drop operations, property editors, and code editors. You can also preview how your pages will look on different devices.
Install a sample app: You can use the Gallery option to install a sample app from a list of pre-built applications that demonstrate various features and best practices of Oracle APEX. You can also use the Packaged Apps option to install a packaged app from a list of ready-to-use applications that provide common functionality and solutions.
Create a new app: You can use the Create App option to create a new app from scratch or from an existing data source using the Create Application Wizard. You can also use the From a File option to create a new app from a file that contains data or metadata.
The other option is incorrect because:
Run SQL scripts and commands: You cannot use the App Builder component to run SQL scripts and commands. You can use the SQL Workshop component to run SQL scripts and commands using the SQL Commands or SQL Scripts tools.
Verified References: [About App Builder] [Using Page Designer] [Installing Sample Apps] [Installing Packaged Apps] [Creating Applications]