Explanation:

• Nagarhole National Park is a national park located in Kodagu district and Mysore district in Karnataka, India.
• Mukurthi National Park is a 78.46 km² protected area located in the western corner of the Nilgiris Plateau west of Ootacamund hill station in the northwest corner of Tamil Nadu state in the Western Ghats mountain range of South India.
• Silent Valley National Park, is a national park in Kerala, India. It is located in the Nilgiri hills, has a core area of 89.52 km², which is surrounded by a buffer zone of 148 km².

Hence option 4th is correct.