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

General formula of (X) indicates that it is an alkyne, which on monohydroboronation with `Br_(2)H_(6)`, followed by protolysis with `H^(+)` gives pure cis-alkene (A).
`[-C-=C-overset(B_(2)H_(6))to[-CH=overset(|)C-]_(3)overset(H^(+))toCH=CH-]`
A) on reductive ozonolysis gives two aldehydes (B) and (C). (B) undergoes Cannizzaro's reaction, hence, it should not contain any `alpha`-hydrogen (i.e., at `alpha`-position) there should be quaternary carbon. Reactions may be given as:

Only (B) gives Cannizzaro's reaction.
Alkene (A) exist in following two geometrical isomes (A-1) and (A-2) and (A-2) is more stable.