Ambubachi Mela is a major Hindu festival celebrated at:

Kamakhya Temple
Umananda Temple
Navagraha Temple
Mahabhairav Temple

The correct answer is (a) Kamakhya Temple.

Ambubachi Mela is a major Hindu festival celebrated at the Kamakhya Temple in Guwahati, Assam, India. The festival is held every year during the monsoon season, from June to July, and marks the annual menstrual cycle of the goddess Shakti.

The Kamakhya Temple is a Shakti Peetha, one of the 51 sacred sites associated with the goddess Shakti. The temple is located on the Nilachal Hill, overlooking the Brahmaputra River. The temple is dedicated to the goddess Kamakhya, who is worshipped as the goddess of fertility and sexuality.

The Ambubachi Mela is a five-day festival. The first day of the festival is called the “Garbha Pujan”, which is a ritual to purify the temple. The second day is called the “Abhishekam”, which is a ritual to bathe the goddess with milk, honey, and other offerings. The third day is called the “Maha Puja”, which is the main ritual of the festival. The fourth day is called the “Bhog”, which is a ritual to offer food to the goddess. The fifth and final day is called the “Utsava”, which is a day of celebration and feasting.

The Ambubachi Mela is a major tourist attraction in Assam. The festival attracts thousands of pilgrims from all over India and the world. The festival is a time of religious devotion, but it is also a time of celebration and feasting.