5ab^2 - 12a^2b + 3ab + ab^2 + 4a^2b

(a) 6ab^2 + -8a^2b + 3ab
(b) -7ab^2 + 8a^2b + 3ab
(c) 6a^2b^4 - 8a^4b^2 + 3ab
(d) 5a^2b^4 + -8a^4b^2 + 3ab