The correct answer is: b) Kumbakonam.
The Mahamaham festival is a Hindu festival held once every 12 years in the town of Kumbakonam in the Indian state of Tamil Nadu. The festival is dedicated to the god Vishnu and his consort Lakshmi. The main event of the festival is a holy dip in the temple tank of Kumbakonam, which is believed to have miraculous powers.
The temple tank of Kumbakonam is called the Mahamaham tank. It is a large artificial lake that is said to have been built by the Chola king Rajendra Chola I in the 11th century. The tank is believed to be one of the holiest places in Hinduism.
The Mahamaham festival is a major tourist attraction. Millions of people from all over India and the world visit Kumbakonam to take part in the festival. The festival is a time of great religious fervor and celebration.
The other options are incorrect because they are not the towns where the Mahamaham festival is held. Madurai, Thanjavur, and Srirangam are all important Hindu pilgrimage sites, but they do not host the Mahamaham festival.