Explanation
The commission yn column will restrict acceptable values to TRUE or FALSE because of the /check modifier in the column name. This modifier adds a check constraint to the column based on the values specified after it.
The yn suffix indicates that the column is of type VARCHAR2(1). The other options are incorrect because they do not reflect the effect of the /check modifier or the yn suffix. Verified References: Using Quick SQLAbout Quick SQL Shorthand Syntax

Explanation
There are three different ways in which you can add a checkbox to a page in APEX:
Drag and drop the checkbox item into the Layout pane: In Page Designer, you can drag and drop items from the Gallery pane into the Layout pane to create them on your page. To create a checkbox item, expand the Items node in the Gallery pane and drag and drop Checkbox into the Layout pane.
Right click Body in the Rendering Tree and add a New Page Item as Checkbox Type: In Page Designer, you can right click any node in the Rendering tree andselect Create to create a new component under that node. To create a checkbox item under the Body node, right click Body and select Create > New Page Item > Checkbox.
Use the context sensitive menu in the Gallery pane: In Page Designer, you can use the context sensitive menu in the Gallery pane to create items on your page. To create a checkbox item using this method, expand the Items node in the Gallery pane and right click Checkbox. Then select Create Checkbox.

Explanation
Dynamic actions provide a way to define complex client-side behavior declaratively without the need for JavaScript. You can create dynamic actions on items, buttons, or regions of a page by specifying an event, a condition, an action, and other properties1. However, more dynamic actions you add to a page, the greater your overall page size. This can affect the performance and user experience of your application2. It is possible to debug dynamic actions from the Developer Toolbar by using the Debug option3. Dynamic actions do not require complex client-side JavaScript code, but they can optionally include custom JavaScript code as an action or a condition1.

Explanation
When the customer name is clicked in the report, the Customer Details form dialog page is displayed. This is a page rendering event, which means the page is generated and sent to the browser. When the items in the form dialog are updated and the user clicks Apply Changes, the page process is executed and the items from the page are used to update and commit the underlying table in the Oracle Database. This is a page processing event, which means the page is submitted to the server and processed by APEX. Page validation is also a part of page processing, but it is not a separate event. Page refresh is not an event, but an action that can be triggered by a dynamic action or a process

Explanation
You can create a report with form in Oracle APEX by using either the Create Application Wizard or the Create Page Wizard. The report can be either an interactive report or a classic report, and the form can be either a single row form or a multi row form. The report with form combination enables you to view and edit data from a table or a query in a single page. You can also customize the report and form attributes, such as the columns, regions, buttons, validations, processes, and so on. Verified References: [Creating a Report Using the Create Page Wizard - Oracle], [Creating a Report with Form on Table - Oracle]