Consider the derivation of an alternate form of the
cosine double angle identity.

Step
1. cos(2x) = cos(x) - sin²(x)
2. cos(x) - (1 - cos²(x))
3. cos(x)-1-cos²(x)
4. 2cos²(x) - 1

What is the error in this derivation?

A. In step 1, cos(2x) is equal to cos²(x) + sin²(x).
B. In step 2, sin²(x) should have been replaced with 1 + cos²(x).
C. In step 3, cos²(x) - 1- cos²(x) should be cos²(x) - 1 + cos²(x).
D. In step 4, 2cos²(x) - 1 should be 1-2cos²(x).