Step 1: About Silent Valley National Park
It is a famous national park known for its rich biodiversity and undisturbed tropical rainforest ecosystem.
Step 2: Location
Silent Valley National Park is located in the Palakkad district of Kerala.
Step 3: Importance
The park is part of the Nilgiri Biosphere Reserve and is home to many rare and endangered species.
Thus, Option (C) Palakkad is correct.