Simplify (1-2z)(1+2z)


I've already done the math and gotten - 4z^2+1 (which is correct when I check) but it's not in my list for the multiple choice question I'm on. The answers I have are the following:


A) 1 - 4z

B) 1 - 4z - 4z^2

C) 4z^2 - 4z - 1

D) 4z^2 - 1


If someone could tell me which answer would be correct in this situation, that would be amazing. Thank you to anyone who takes the time to figure this out!