The correct answer is b) Idukki.
The Idukki Dam is a gravity dam on the Periyar River in the Idukki district of Kerala, India. It is the largest hydroelectric project in India and the second-largest in Asia. The dam was constructed between 1961 and 1974 and is operated by the Kerala State Electricity Board.
The dam has a height of 168 meters (551 feet) and a length of 365 meters (1,201 feet). It has a gross storage capacity of 2,400 million cubic meters (85 billion cubic feet) and a live storage capacity of 1,200 million cubic meters (42 billion cubic feet). The dam generates 2,100 megawatts of electricity.
The Idukki Dam has been controversial since its construction. The dam has displaced thousands of people and has been blamed for environmental problems, including the decline of the fish population in the Periyar River. However, the dam is also credited with providing electricity to millions of people in Kerala and with helping to improve the state’s economy.
The other options are:
a) Sabarigiri is a proposed hydroelectric project in the Idukki district of Kerala, India. The project has been controversial since its inception, and has been opposed by environmental groups and local communities.
c) Idamalayar is a hydroelectric project in the Idukki district of Kerala, India. The project was completed in 1974 and has a capacity of 120 megawatts.
d) Sholayar is a hydroelectric project in the Palakkad district of Kerala, India. The project was completed in 1964 and has a capacity of 100 megawatts.