Explanation: Pongal is a traditional harvest festival celebrated in Tamil Nadu, India, and is particularly significant in Chennai. The festival marks the beginning of the Tamil month of Thai, which usually falls in mid-January. Pongal is a four-day festival that includes thanksgiving to nature, the sun, and cattle. The festival is named after the Tamil word "ponga," which means "to boil over," symbolizing the abundance of the harvest.
The first day of Pongal is known as Bhogi, where people discard old belongings and focus on new beginnings. The second day is the main Pongal day, dedicated to the sun god, Surya. On this day, a special dish called "pongal" is prepared, which is a sweet rice dish cooked in milk and jaggery. The third day is Mattu Pongal, where cattle are decorated and worshipped, as they are considered essential for agriculture. The fourth day is Kaanum Pongal, a day for family reunions and visiting relatives.
Pongal is not only a celebration of the harvest but also a time for cultural and social activities. People decorate their homes with kolams (rangoli), wear new clothes, and exchange gifts. The festival is a significant part of Tamil culture and is celebrated with great enthusiasm in Chennai and other parts of Tamil Nadu.
In contrast, Holi is a festival of colors celebrated in North India and other parts of the country, but it is not a harvest festival. It is associated with the spring season and the legend of Holika. Bihu is a harvest festival celebrated in Assam, a state in Northeast India, and is not related to Tamil Nadu or Chennai. Therefore, Pongal is the correct answer as it is the harvest festival celebrated in Chennai and Tamil Nadu.