You are developing a Windows Store app by using HTML5. The app will be optimized for accessibility. The app
must meet the following accessibility requirements:
Provide support for navigating all user interfaceelements. Provide support for invoking default functionality
on the user interface.
Provide support for use of a computer keyboard.
You need to ensure that the app meets the accessibility requirements. Which actions should you perform?
(Each correct answer presents part of the solution.Choose all that apply.)

A.
Set the tabIndex attribute for interactive elements. Dynamically manage the tabIndex attribute for composite
elements.

B.
Set the aria-live attribute of user interface elements to polite for important content that changes
dynamically.

C.
Ensure that visible text has a minimum luminositycontrast ratio of 1:1 against the background.

D.
Implement event handlers for invoking default functionality.