Solution: Silent Valley National Park is located in Palakkad/Palghat district of Kerala. It is situated on Nilgiri Hills of Western Ghat not Nallamalai Range. Therefore statement 1 is wrong. Pathrakkadavu hydroelectric project was proposed by Kerala State Electricity Board at a distance of 1 km from Silent Valley National Park. Thus, statement 2 is correct. Kunthi River is the tributary of Thuthapuzha River and originates in the Silent Valley. Thus, statement 3 is also correct. Thus, the correct answer will be option (c).