The equation $x^{2} + (b/a)x + (c/a) = 0$ has two real roots $\alpha$ and $\beta$. If $a > 0$, then the area under the curve $f(x) = x^{2} + (b/a)x + (c/a)$ between $\alpha$ and $\beta$ is\\
(a) $(b^{2} - 4ac)/2a$\\
(b) $(b^{2} - 4ac)^{3/2}/6a^{3}$\\
(c) $-(b^{2} - 4ac)^{3/2}/6a^{3}$\\
(d) $-(b^{2} - 4ac)/2a$