Question

let f and g be differentiable
f (1)=4, g(1)=3, f ' (3) = -5
f ' (1)= -4, g ' (1)= -3, g ' (3)= 2
If h(x)= f(g(x)), then h ' (1) = ?
a) -9
b) 15
c) 0
d) -5
e) -12

i have no clue how to do this at all, need some help.