6b^3 + 9b^2 - 12b

Which represents the polynomial in factored form?

(A) 3b^3 (2b^2 + 3b - 4)
(B) 3b (2b^2 + 9b^2 - 12b)
(C) 3b^2 (3b^2 + 6b - 9)
(D) 3b (2b^2 + 3b - 4)