let f and g be inverse functions that are differentiable for all x. If 9(-5)=7 and f'(7)=3, which of the following statements must be false?
I. g'(3)=-1/3
II. g'(-5)=1/3
III. g'(7)=1/3

a. I only
b. II only
c. III only
d. I and III only
e. I,II, and III