In the figure given above $\Delta ABC \sim \Delta EDC$. Which of the following must be true.
$\begin{array}{1 1} (a)\;\overline{AE} // \overline{BD} \\ (b)\; \angle{ABC} = \angle{EDC} \\ (c)\; \angle{ACB}=\angle{DEC} \\ (d)\; \text{None of the above} \end{array}$
