The correct option is A Methane
Methane can not be prepared by Wurtz reaction.
In wurtz reaction, two molecules of alkyl halides combine (on heating with sodium metal in presence of dry ether as solvent) to produce higher alkanes containing even number of carbon atoms.
CH3−I+2Na+I−CH3dry ether−−−−−→△CH3−CH3+2NaI
A mixture of two different alkyl halides on heating with sodium will give three different alkanes.