Would you please show an easy way to solve this:

a(x) = x^3 +3x^2 + 5x

b(x) = 5x^2 + 17x + 16

Polynomial a(x) and b(x) are defined above. Which of the polynomials below has a factor of 3x + 2 ?

(A) l(x) = a(x)+ b(x)

(B) m(x) = 3a(x) + b(x)

(C) n(x) = a(x) – 3b(x)

(D) p(x) = 2a(x) + 3b(x)