Explanation:

- In January 2021, the Central Government announced a committee to protect the unique language, culture, and land of Ladakh.

- G Kishan Reddy (Option 3) was appointed as the head of this committee. At the time, he served as the Minister of State for Home Affairs. His role on the committee aligns with his responsibilities regarding internal security and regional affairs.

- Arjun Munda (Option 1) is the Minister of Tribal Affairs, and his primary responsibilities involve the welfare and development of tribal communities in India.

- Piyush Goyal (Option 2) is involved in various ministerial roles, traditionally related to commerce and industry, and not typically associated with regional cultural protection initiatives.

- Raj Kumar Singh (Option 4) is an Indian politician known for his roles in energy and power sectors rather than cultural or regional affairs.

- Correct Answer: Option 3 - G Kishan Reddy