The graph below shows a portion of the curve defined by the quartic polynomial P(x)=x^{4}+a x^{3}+b x^{2}+c x+d. Which of the following is the smallest?
Answer Choices
A. P(-1)
B. The product of the zeros of P
C. The product of the non-real zeros of P
D. The sum of the coefficients of P
E. The sum of the real zeros of P