Final answer:
Out of the given options (Alkyne, Ester, Amine), only Esters contain a carbonyl group.
Step-by-step explanation:
The functional groups that contain a carbonyl group are aldehydes, ketones, carboxylic acids, and esters. Among the options given: 1) Alkyne does not contain a carbonyl group, 2) Ester contains a carbonyl group, represented as -CO₂R where R is an organic substituent, and 3) Amine does not contain a carbonyl group. Therefore, the functional group that contains a carbonyl group in the given options is an Ester.