If f(x) = 2x^2 and g(x)= x^2 + 2x, which expression represents f(g(x))?

A) 2x^4 + 4x^2
B) 4x^4 + 4x^2
C) 2x^4 + 8x^2
D) x^4 + 4x^3 + 4x^2
E) 2x^4 + 8x^3 + 8x^2