Suppose g(x) is differentiable at x=−9,g(−9)=3, and g′(−9)=0. Select all statements that must be true.
a. g(x) is continuous at x=9
b. lim h→0 hg(−3+h)−g(−3) =9
c. lim x→9 g(x) exists
d. lim x→−3 g(x)=0
e. none of the above