Explanation:

- Gangaur is a vibrant festival celebrated primarily among the womenfolk.

- It marks the worship of Gauri, a manifestation of Goddess Parvati, celebrating marriage and harvest.

- The festival is most prominently observed in Rajasthan with grand processions and cultural performances.

- Option 1: Rajasthan - Correct Answer: Rajasthan is the state where Gangaur is celebrated with great enthusiasm, featuring processions, songs, and rituals honoring Gauri.

- Option 2: Himachal Pradesh - While rich in cultural festivals, Himachal Pradesh is not known for Gangaur.

- Option 3: Tripura - Tripura has its unique festivals, but Gangaur is not one of them.

- Option 4: Arunachal Pradesh - This state celebrates many local festivals, but Gangaur isn’t traditionally one of them.