Ester naming: alkyl from alcohol, alkanoate from acid Steps:

• Parse name: "propyl methanoate" = propyl alcohol part + methanoate (from methanoic acid, HCOOH).
• Methanoate group: HCOO- (formyl from formic acid).
• Propyl group: CH3CH2CH2- (n-propyl).
• Combine: H-C(=O)-O-CH2CH2CH3.
• Check options: none match this formula.

Why D is correct:

• D does not match; it is ethyl propanoate (CH3CH2COO-CH2CH3), not propyl methanoate.

Why the others are wrong:

• A: Propyl ethanoate (CH3COO-CH2CH2CH3), wrong acid part (ethanoate, not methanoate).
• B: Methyl propanoate (CH3CH2COO-CH3), wrong alkyl and acid parts.
• C: Butanoic acid (CH3CH2CH2COOH), a carboxylic acid, not an ester.

Final answer: None of the above