Both methane and ethane may be obtained by suitable one step reaction from

Methyl iodide produces ethane in the Wurtz reaction and methane in the reduction reaction. $\begin{array}{l}{\mathrm{CH}}_3\mathrm{I}+2\mathrm{H}\stackrel{\mathrm{ZnHCl}}{⟶}{\mathrm{CH}}_4+\mathrm{HI}\\ {\mathrm{CH}}_3\mathrm{I}+2\mathrm{Na}+{\mathrm{ICH}}_3\underset{\text{ Dther }}{\stackrel{\text{ Dry }}{⟶}}{\mathrm{CH}}_3-{\mathrm{CH}}_3+2\mathrm{NaI}\end{array}$ 

Hence, the correct option (A). Methyl iodide.