If f(x)=x2f(x) = x^2f(x)=x2 and g(x)=2x+3g(x) = 2x+3g(x)=2x+3, which of the following is (g∘f)(x)(g \circ f)(x)(g∘f)(x)?
2x2+32x^2+32x2+3
4x2+12x+94x^2+12x+94x2+12x+9
x2+2x+3x^2+2x+3x2+2x+3
2x+32x+32x+3