An organic base (X) reacts with nitrous acid at $$0 ^\circ\text{C}$$ to give a clear solution. Heating the solution with KCN and cuprous cyanide followed by continued heating with conc. HCl gives a crystalline solid. Heating this solid with alkaline potassium permanganate gives a compound which dehydrates on heating to a crystalline solid. X is -

A

B

C

D