If f (x) = - 3x4 - 2x3 + 3x2, and g (x) = 3x4 - 4x3 + x2 then f (x) + g (x) =

A. 2x3 - 2x2

B. - 6x3 + 4x2

C. - 3x4 - 6x3 + 4x2

D. 3x4 + 2x3 - 2x2

I'm assuming the the numbers coming after the variables are meant to be exponents, and if I'm wrong just let me know

-3x^4 - 2x^3 + 3x^2 + 3x^4 - 4x^3 + x^2, rearrange to have like terms in order

-3x^4 + 3x^4 - 2x^3 - 4x^3 + 3x^2 + x^2, now simplify

0 - 6x^3 + 4x^2