The correct option is C Kali Bein
In 2000, Sant Balbir Singh set out to clean the Kali Bein river with a large team of volunteers. He wanted to teach people the importance and benefit of protecting and cleaning the river. After nearly a decade, they managed to restore the river’s natural flow of clean water. Hearing of his efforts, the local government collaborated with Sant Balbir Singh in creating a low-cost sewage system that treats sewage waters for usage in agriculture.