The correct answer is b) Eco-tourism.
Kerala is a state in India that is known for its beautiful beaches, backwaters, and forests. It is also home to a wide variety of wildlife, including elephants, tigers, and monkeys. This makes it a popular destination for eco-tourists, who are interested in experiencing nature and learning about the local culture.
Winter sports are not typically associated with Kerala, as the climate is tropical. Desert safaris are also not common in Kerala, as there are no deserts in the state. Historical sites are also not the main attraction for tourists in Kerala, although there are some interesting temples and palaces to visit.
Therefore, the correct answer is b) Eco-tourism.