Question

please solve this and tell how the answer came​

Answer 1

I think it's crowd option 2

Answer 2

Option 2) Crowd.

Choir, heap, pile, crowd.

These words are similar as they represent the meaning for "a group of many things/people". In other words, these are collective nouns. A choir of singers, a heap of garbage, a pile of books and a crowd of fans, etc.