# In which of the following reactions the product is an ether ?

$\begin {array} {1 1} (a)\;C_6H_6+CH_3COCl/anhydrous\;AlCl_3 & \quad (b)\;C_2H_5Cl+aq.KOH \\ (c)\;C_6H_6+C_6H_5C_0Cl/ anhydrous AlCl_3 & \quad (d)\;C_2H_5Cl+C_2H_5ONa \end {array}$