Answer: Choice C. v^4w^2+15v^2w^3+2
================================================
Work Shown:
(9v^4+2)+v^2(v^2w^2+2w^3-2v^2)-(-13v^2w^3+7v^4)
9v^4+2+v^2*v^2w^2+v^2*2w^3+v^2*(-2v^2)-(-13v^2w^3)-(7v^4)
9v^4+2+v^4w^2+2v^2w^3-2v^4+13v^2w^3-7v^4
(9v^4-7v^4-2v^4)+v^4w^2+(2v^2w^3+13v^2w^3)+2
(0v^4)+v^4w^2+(15v^2w^3)+2
v^4w^2+15v^2w^3+2
