Which pane displays commands that change relative to the activity taking place in the presentation window's main work area?

The correct answer is the "Selection Pane." The pane that displays commands that change relative to the activity taking place in the presentation window's main work area is the Selection Pane. Selection pane is where you can easily select the elements that you included in the presentation's main work area.

I believe the answer is: Task

The main function of Task Pane in windows is to enable windows users to manipulate the data that exist inside a document.

This feature could be accessed by clicking view - Task Pane or by using a keyboard shortcut Ctrl+f1