Answer:
The correct answer is option c. the Quick Access Toolbar.
Step-by-step explanation:
The Quick Access Toolbar is a navigation bar included in the office package, which is presented independently as a window in which you can navigate and find useful commands for the person who is using it.
You can add command buttons to speed up the job, although you cannot change the size of those buttons.
Given this information we can say that the correct answer is option c. the Quick Access Toolbar.