AHSME 1967 Problem 7

If $\frac{a}{b}<-\frac{c}{d}$ where $a$, $b$, $c$, and $d$ are real numbers and $bd \not= 0$, then: $\text{(A)}\ a \text{must be negative} \text{(B)}\ a \text{must be positive}$ $\text{(C)}\ a \text{must not be zero} \text{(D)}\ a \text{can be negative or zero, but not positive } \\ \text{(E)}\ a \text{can be positive, negative, or zero}$