This river, locally known as Nila, is the second-longest river in Kerala:

The correct answer is: d) Bharathappuzha River.

The Bharathappuzha River, locally known as Nila, is the second-longest river in Kerala, India. It is 209 kilometers (130 mi) long and drains an area of 21,140 square kilometers (8,160 sq mi). The river originates in the Western Ghats and flows through the districts of Palakkad, Malappuram, and Thrissur before emptying into the Arabian Sea.

The Bharathappuzha River is a major source of irrigation and drinking water for Kerala. It is also a popular tourist destination, known for its scenic beauty and wildlife.

The other options are incorrect because:

• The Kuttiyadi River is a tributary of the Bharathappuzha River.
• The Chaliyar River is a river in the Malappuram district of Kerala.
• The Periyar River is a river in the Idukki district of Kerala.