In the above reaction, the structural formula of (A), "X" and "Y" respectively are:

Explanation: The evolution of nitrogen gas $$N_2$$ indicates that the reaction involves an arenediazonium salt.

Ethanol acts as a mild reducing agent and replaces the diazonium group $$-N_2^+Cl^-$$ with hydrogen.

Since the final product is anisole $$C_6H_5OCH_3$$, the starting compound $$A$$ must be methoxybenzenediazonium chloride.

The molecular formula $$C_7H_7N_2OCl$$ matches methoxybenzenediazonium chloride.

During the reaction, ethanol is oxidized to acetaldehyde $$CH_3CHO$$, and the chloride ion combines with the proton released from ethanol to form $$HCl$$.

Thus:

$$A = p\text{-methoxybenzenediazonium chloride}$$

$$X = CH_3CHO$$

$$Y = HCl$$