1. ## differentiation

Suppose that f is an odd function; i.e., f(-x)=-f(x) for all x. Suppose that f'(x) exists. Which of the following must necessarily be equal to f'(-x)?

A) f'(x)
B) -f'(x)
C) 1/(f'(x))
D) -1/(f'(x))
E) None of the above