The correct answer is: a) Birdwatching.
Kerala’s backwaters are a popular destination for birdwatching. The backwaters are a network of canals, rivers, and lakes that cover over 900 square kilometers of the state. The backwaters are home to a variety of birds, including kingfishers, herons, egrets, and pelicans. Birdwatchers can take boat tours through the backwaters to see the birds in their natural habitat.
Option b) Wildlife safaris is incorrect because the backwaters are not a popular destination for wildlife safaris. There are no large mammals in the backwaters, and the only wildlife that can be seen there are birds and reptiles.
Option c) Trekking is incorrect because the backwaters are not a popular destination for trekking. The backwaters are a flat area, and there are no mountains or hills to trek.
Option d) Adventure sports is incorrect because the backwaters are not a popular destination for adventure sports. The backwaters are a calm and peaceful place, and there are no opportunities for adventure sports such as white-water rafting or bungee jumping.