Does the set of residue classes (mod 3) form a group with respect to modular addition?

A. Yes

B. No

C. Can’t Say

D. Insufficient Data

I have been asked this question in an interview for job.

The doubt is from Groups Rings and Fields topic in portion Basic Concepts in Number Theory and Finite Fields of Cryptograph & Network Security

The correct answer is A. Yes

The explanation is: Yes. The identity element is 0, and the inverses of 0, 1, 2 are respectively 0, 2, 1.