Hydrocarbon (X), `C_(7)H_(12)`, on reaction with boron hydride followed by treatment with `CH_(3)COOH` yields (A). On reductive ozonolysis (A) yields a mixture of two aldehydes, (B) and (C ). Of these, only (B) can undergo Cannizzaro reaction. (A) exists in two geometrical isomer, `(A-1)` and `(A-2)`, of which `(A-2)` is more stable. Gives structures of (X), (A), (B), (C ), `(A-1)`, and `(A-2)` with proper reasoning.

Explanation

i. D.U. in (A) `= 2^(@)` [suggests one `(C-=C)` bond, since (A) undergoes reaction with `BH_(3)//CH_(3)COOH` to give `(C-=C)` bond which undergoes ozonolysis].
ii. One product of ozonolysis undergoes Cannizzaro reaction, which must be an aldehyde without `alpha`-H atom. Compound (B)must be `(Me_(3)C-CHO)` (five C atoms).
Proceed reverse: