Which sentence correctly forms the plural of the letters PDF?

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

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

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

yinshy · Answer

@AnitaS.

anitas. · Answer

A because the other two are possessive and A is plural.