Which of the following azeotropic solutions has the boiling point less than the boiling point of the constituents

Question

$\begin{array}{1 1}(a)\;CH_3CH_2OH\;and\;CHCl_3\\(b)\;CH_3CHO\;and\;CS_2\\(c)\;CHCl_3\;and\;CH_3COCH_3\\(d)\;CS_2\;and\;CH_3COCH_3\end{array}$