Which is equivalent to the following expression?

(3x2+2xy−y2)+(x2+4xy−y2)
(1 point)
Responses

4x4−6xy−2y4
4 x to the 4th power minus 6 x y minus 2 y to the 4th power

4x2+6xy−2y2
4 x squared plus 6 x y minus 2 y squared

3x2−6xy−2y2
3 x squared minus 6 x y minus 2 y squared

4x2+6xy+2y2
4 x squared plus 6 x y plus 2 y squared