#### Answer

$C$

#### Work Step by Step

$(2x+5)(2x-5)=$
...identify which terms correspond to $a $and $b $
in the rule for the product of a sum and difference
($(a+b)(a-b)=a^{2}-b^{2}$)
$a=2x,\ b=5$...substitute for $a $and $b $ in the rule
$(2x+5)(2x-5)=(2x)^{2}-(5)^{2}$...simplify.
=$4x^{2}-25$
Answer: C.