How many quadratic polynomials with real coefficients are there such that the set of roots equals the set of coefficients? (For clarification: If the polynomial is a x^{2}+b x+c, a \neq 0, and the roots are r and s, then the requirement is that \{a, b, c\}=\{r, s\}.)
Answer Choices
A. 3
B. 4
C. 5
D. 6
E. infinitely many