Ester Saponification Reaction Steps:

• Recognize C15H31CO2C16H33 as an ester (RCOOR', R = C15H31, R' = C16H33).
• Heating under reflux with excess aqueous NaOH triggers saponification (base hydrolysis).
• The reaction cleaves the ester bond: RCOOR' + NaOH → RCO2Na + R'OH.
• Products are sodium carboxylate (C15H31CO2Na) and alcohol (C16H33OH).

Why A is correct:

• Matches the standard saponification products, where aqueous NaOH forms the carboxylate salt and neutral alcohol per the reaction RCO2R' + NaOH → RCO2Na + R'OH.

Why the others are wrong:

• B: Shows alcohol as C16H33ONa (alkoxide), but aqueous NaOH does not deprotonate the alcohol (pKa ~16).
• C: Uses inconsistent notation (COONa vs. question's CO2); A aligns with given formula.
• D: Shows both as salts, including alcohol alkoxide, which forms only in anhydrous conditions, not aqueous.

Final answer: A