The correct answer is: A. Mouse becomes inoperative
Access keys are keyboard shortcuts that allow users to access menus, commands, and other features without using the mouse. This can be helpful for users who have difficulty using a mouse, or for users who want to be able to use their keyboard to navigate an application.
Option B is incorrect because access keys do not require the mouse to be fully operative. In fact, access keys can be used even if the mouse is not working at all.
Option C is incorrect because access keys can be used even if the mouse is only partially operative. For example, if the left mouse button is not working, the user can still use access keys to navigate the application.
Option D is incorrect because access keys are not specific to the keyboard. They can be used with any input device that can generate keyboard input, such as a keyboard, a touchscreen, or a speech recognition system.