1955 AHSME Problem 40

The fractions \frac{ax+b}{cx+d} and \frac{b}{d} are unequal if:

\begin{array}{l} \textbf{(A)}\ a=c=1, x\neq 0\qquad\textbf{(B)}\ a=b=0\qquad\textbf{(C)}\ a=c=0\\ \textbf{(D)}\ x=0\qquad\textbf{(E)}\ ad=bc \end{array}

Full credit goes to MAA for authoring these problems. These problems were taken on the AOPS website.