Cyclohexylamine when treated with nitrous acid yields (P). On treating (P) with PCC results in (Q). When (Q) is heated with dil. NaOH we get (R). The final product (R) is:
(1)
(2)
(3)
(4)

A

Structure (1)

B

Structure (2)

C

Structure (3)

D

Structure (4)