Which of the following reactions can be used to prepare methane?

In option (A) Decarboxylation of sodium acetate with $\mathrm{NaOH}$ in presence of $\mathrm{CaO}$ under heating produces methane ${\mathrm{CH}}_3\mathrm{COONa}+\mathrm{NaOH}+\mathrm{CaO}\to {\mathrm{CH}}_4+{\mathrm{Na}}_2{\mathrm{CO}}_3$ 

In option (B) Kolbe's electrolysis produces ethane                 

In option (C) Wurtz reaction produces double the number of carbon atoms in product

In option (D) Hydrogenation of alkenes also produces more than one carbon atoms                    

But the methane contains only one carbon atom