The polynomial f(x)=x^{4}+a x^{3}+b x^{2}+c x+d has real coefficients, and f(2 i)= f(2+i)=0. What is a+b+c+d ?

**Answer Choices**

A. 0

B. 1

C. 4

D. 9

E. 16

The polynomial f(x)=x^{4}+a x^{3}+b x^{2}+c x+d has real coefficients, and f(2 i)= f(2+i)=0. What is a+b+c+d ?

**Answer Choices**

A. 0

B. 1

C. 4

D. 9

E. 16