Hello there!
The answer is D) (x+2)(x-2)
To remember how to factor a difference of perfect squares, the terms, for lack of better words, are divided in half.
Example:
x²: (x+ )(x- )
4: ( +2)( -2)
Do you see what each term "does" to the answer?
(x+2)(x-2)
I really hope this helps!
Best wishes :)