Read the text and determine if the sentence is true (see options at the end):

How to open dll files<br>Understand what a dll file is. A dll (dynamic link library) is a windows file that is used by program to call upon existing functions. Essentially, they allow windows and other programs to gain functionality without having to have that functionality built-in.

Sentence: DLL files are easy to open.
Available choices: a). Yes; b). It's impossible to say; c). No;