The correct answer is a) Periyar Basin.
The Periyar Basin is the largest river basin in Kerala, covering an area of 2,400 square kilometers. It is home to several major hydroelectric projects, including the Idukki Dam, the Cheruthoni Dam, and the Mullaperiyar Dam. These dams provide a significant amount of electricity to the state of Kerala.
The Pamba Basin is the second largest river basin in Kerala, covering an area of 1,800 square kilometers. It is home to the Pamba Dam, which is a major hydroelectric project.
The Bharathapuzha Basin is the third largest river basin in Kerala, covering an area of 1,600 square kilometers. It is home to the Neyyar Dam, which is a major hydroelectric project.
The Chalakudy Basin is the fourth largest river basin in Kerala, covering an area of 1,400 square kilometers. It is home to the Idamalayar Dam, which is a major hydroelectric project.
In conclusion, the majority of Kerala’s hydroelectric projects are concentrated in the Periyar Basin. This is because the Periyar Basin is the largest river basin in Kerala and is home to several major hydroelectric projects.