The correct answer is A. Sun.
Chhath Puja is a Hindu festival dedicated to the Sun God. It is celebrated in India, Nepal, and Bangladesh. The festival is observed over four days, with the main day of the festival falling on the sixth day of the lunar month of Kartik.
On the first day of the festival, people clean their homes and decorate them with flowers and rangolis. They also bathe in the river or a holy pond. On the second day, people fast and offer prayers to the Sun God. They also make offerings of food and flowers to the Sun God. On the third day, people again fast and offer prayers to the Sun God. They also take a dip in the river or a holy pond. On the fourth day, people break their fast and celebrate the festival with feasting and dancing.
Chhath Puja is a major festival in India and Nepal. It is a time for people to thank the Sun God for his blessings. It is also a time for people to pray for the well-being of their family and friends.
The other options are incorrect because they are not the Sun God. Vishnu is the preserver god in Hinduism. Shiva is the destroyer god in Hinduism. Rama is an avatar of Vishnu.