Answer:
D.
Step-by-step explanation:
f(x)·g(x)=(x³+2x²+3x+1)(4x-5)
=[tex]4x^{4} +8x^{3} +12x^{2} +4x-5x^{3} -10x^{2} -15x-5[/tex]
=[tex]4x^{4} +3x^{3} +2x^{2} -11x-5[/tex]