In a reaction,

reagents 'X' and 'Y' respectively are :

The structures of major products A, B and C in the following reaction are sequence.

Cyclohexylamine when treated with nitrous acid yields $(\mathrm{P})$. On treating $(\mathrm{P})$ with $\mathrm{PCC}$ results in (Q). When $(\mathrm{Q})$ is heated with dil. $\mathrm{NaOH}$ we get $(\mathrm{R})$ The final product (R) is :

Consider the following reaction

The correct statement for product B is. It is