What does the Disk Defragmenter tool do?

A. It analyzes the storage capacity of the disk and defragments it.

B. It scans the system for errors and attempts to repair them in the defragmented section.

C. It shows how much disk space is wasted by defragmented files.

It's kind of a mix between A and C there are some defragmenting tools that show you how much of your PC is wasted by program files. And in some defragmenting tools, it shows you all the files that are fragmented and gives you the option to defrag them or not. So the best answer would be A.