Step 1: Cannizzaro Reaction.
The Cannizzaro reaction is a base-induced disproportionation of non-enolizable aldehydes, resulting in the formation of an alcohol and an acid, but not specifically introducing a carboxyl group (\( \text{-COOH} \)). The other reactions are directly involved in the introduction of the carboxyl group.
Step 2: Conclusion.
The correct answer is (A), Cannizzaro reaction.