6. If f(x) = x2 - 1, which of the following is equal to g(x) = f(x - 3)?
A.g(x) = x/ +8
B.g(x) = x2 + 6x+8
C.g(x)= x2 - 6x + 8
D.g(x) = x2 + 6x- 10