Explanation:

- In the 2020-21 period, India continued to see strong milk production across various states.

- Uttar Pradesh: Often ranks as the leading state in milk production due to its large dairy farming industry.

- Gujarat: Known for its well-organized dairy industry, but doesn't top the list.

- Andhra Pradesh: Has significant milk production but is not the top state.

- Rajasthan: Strong dairy presence, particularly with indigenous breeds.

Uttar Pradesh is indeed the state that ranks first in milk production for the 2020-21 period.