(c)
In Wurtz reaction alkyl halide reacts with sodium in presence of dry ether to give alkanes $e.g.,$
$C_{2}H_{5}\boxed{Cl + 2Na + Cl}C_{2}H_{5}\overset{\rightarrow}{(dry\ ether)}C_{4}H_{10} + 2NaCl$
butane
In Wurtz reaction wet ether is not used because wet ether destroy the sodium metal.