1. Use the reaction with concentrated NaOH

   The compound gives benzyl alcohol as one of the products with conc. $NaOH$.

   This is characteristic of the Cannizzaro reaction, which is shown by aldehydes having no $\alpha$-hydrogen.

   Since one product is benzyl alcohol $\left(C_6H_5CH_2OH\right)$, the aldehyde involved must be benzaldehyde or a substituted benzaldehyde that can disproportionate to give the corresponding alcohol.

2. Use the molecular formula

   Given formula: $C_8H_8O_2$

   Benzaldehyde has formula $C_7H_6O$.

   Compared to benzaldehyde, the given compound has one extra $CH_2O$ unit overall, suggesting a methoxy-substituted benzaldehyde: $C_6H_4(OCH_3)(CHO)$ whose molecular formula is indeed $C_8H_8O_2$

   So the compound is some methoxy benzaldehyde isomer.

3. Use the aldol reaction clue

   The compound reacts with acetophenone to form a single cross-aldol product in base.

   In cross-aldol (Claisen–Schmidt) condensation, acetophenone provides the enolate and the aldehyde acts as the electrophile.

   For a single product, the aldehyde should not have enolizable hydrogens (true for aromatic aldehydes like methoxy benzaldehydes), and the structure should be such that no mixture of geometrical/constitutional products is expected from different reactive sites.

   Among methoxy benzaldehydes, the standard structure fitting both clues is anisaldehyde (methoxybenzaldehyde). The Cannizzaro clue is especially important: on reaction with conc. $NaOH$, it gives the corresponding alcohol and acid salt. If the aldehyde is $p$-methoxybenzaldehyde (anisaldehyde), it has no $\alpha$-H and undergoes Cannizzaro.

4. Check the Cannizzaro product statement carefully

   The problem says the compound gives benzyl alcohol as one of the products. In many such questions, this points to an aromatic aldehyde without $\alpha$-H. The intended structure among the options is the benzaldehyde derivative that matches $C_8H_8O_2$ and undergoes Cannizzaro.

   Therefore the structure is methoxybenzaldehyde, specifically the option corresponding to anisaldehyde.

5. Match with stored answer

   The stored correct answer is A. This is consistent with the required structure.

Final Answer: A