Esters provide fruity flavors in non-alcoholic drinks

Steps:

• Identify functional groups: A is an alpha-hydroxy acid, B is a carboxylic acid, C is an ester, D is an alcohol.
• Recall flavoring compounds: Esters like ethyl acetate mimic fruit scents and are used in beverages.
• Eliminate alcohols and acids: Alcohols violate non-alcoholic rule; acids add sourness but aren't primary flavorings.
• Confirm C: Matches ethyl ethanoate formula, safe and common in drinks.

Why C is correct:

• Ethyl ethanoate (CH3COOCH2CH3) is an ester that imparts a sweet, fruity aroma, commonly used as a flavoring agent in non-alcoholic beverages per food chemistry standards.

Why the others are wrong:

• A: Lactic acid (CH3CH(OH)COOH) is sour and used as an acidulant, not a primary flavoring.
• B: Propanoic acid (CH3CH2COOH) has a rancid odor and is too acidic for flavoring.
• D: Propan-1-ol (CH3CH2CH2OH) is an alcohol, prohibited in non-alcoholic drinks.

Final answer: C