I would belive it would be be A
congregation(,<span>a group of people assembled for religious worship.</span> )
Could you add me as best answer?
Another perspective of the poem could what the girl is thinking, or what the lady at the store is thinking or said, or even a father or stranger that had contact (just talked to them) with them for a bit.
Answer:
it is a comma because you have to have a cordinative adjective to have a comma
Explanation: