Question

Factor the polynomial.

Answer 1

It is answer choice A because you have to take the the GCF of each number which is 2x. Then if you were to divide the numbers by 2x you would put those numbers in the brackets. 
$2x( x^{2} +2x+4)$ because $2x^3/2 x = x^{2}$ and $4 x^{2} /2x = 2x$ and $8x/2x = 4$

Answer 2

Factor out 2x to get 2x(x^2+2x+4).  This cannot be factored further, so A is the answer.