Correct Option: D

Silent Valley National Park, is located in the Nilgiri Hills, Palakkad District in Kerala. The park is one of the last undisturbed tracts of South Western Ghats montane rain forests and tropical moist evergreen forest in India. Plans for a hydroelectric project that threatened the parks high diversity of wildlife stimulated an environmentalist Social Movement in the 1970s called Save Silent Valley which resulted in the cancellation of the project and creation of the park in 1980.