Sorry for the stupid question, this is still not clear for me

When the analisis of a drive is completed, i get a list of fragmented files. Ok.

Then i can:
A ) Check all them and click the Defrag button
B ) Right click the drive and select 'Defrag Drive'
from the right click menu.

What's the difference?

Answers:
A ) Only the checked files will be defragmented
B ) The whole drive space will be defragmented
C ) There is no difference at all.

Thanks in advance

Answer (A)
Checking the files and pressing defrag does exactly that, it defrags only the files you've checked. Right clicking 'Defrag Drive' Defrags the drive and also defrags the free space on the drive.

MrRon

Thanks !