Answer:
A, 16x^9
Step-by-step explanation:
You apply the function f to x, then apply the function f to that.
f(x)=2x^3
f(f(x))=f(2x^3)=2(2x^3)^3 = 2*2^3*(x^3)^3 = 2*8*x^(3*3)=16x^9
