For which of the following function f is f(x)=f(1-x) for all x?

A. f(x)= 1-x
B. f(x)= 1-x2 (x square)
C. f(x)= x2 - (1-X)2
D. f(x)= x2(1-X)2
E. f(x)= x/1-x

Thank you

Ali