The correct answer is: a) Unique biodiversity.
Silent Valley National Park is a national park in the Western Ghats of Kerala, India. It is known for its unique biodiversity, including a variety of plants and animals that are found nowhere else in the world. The park is also home to a number of waterfalls, including the Athirappilly Falls, which is one of the highest waterfalls in India.
The park was established in 1980 to protect the Nilgiri tahr, a critically endangered mountain goat. The park is also home to a number of other endangered species, including the lion-tailed macaque, the Nilgiri langur, and the Indian elephant.
The park is a popular tourist destination, and offers a variety of activities, including trekking, camping, and birdwatching.
The other options are incorrect because:
- b) Waterfalls: The park is home to a number of waterfalls, but it is not known for its waterfalls.
- c) Historical monuments: The park does not have any historical monuments.
- d) Beaches: The park is located in the Western Ghats, which is a mountain range. There are no beaches in the park.