Which sentence correctly forms the plural of the letters PDF?

A.
Changing documents into PDFs' isn't too difficult.

B.
Changing documents into PDFs isn't too difficult.

C.
Changing documents into PDF's isn't too difficult.

Question

Which sentence correctly forms the plural of the letters PDF?
 
 A.
Changing documents into PDFs' isn't too difficult.
 
 B.
Changing documents into PDFs isn't too difficult.
 
 C.
Changing documents into PDF's isn't too difficult.

anonymous · Answer

well putting an ' before the s is usually possessive, and the PDFs do not own anything. I believe it could be similar to cats or dogs, we are just looking for the plural, so we wouldn't have an apostrophe at all. What do you think the answer is?

anonymous · Answer

Is it B?

anonymous · Answer

I would say so, but you can get another opinion if you don't think so. I am just helping you form a conclusion, but you do not have to go with my answers :)

anonymous · Answer

you there? what do you think?