The main purpose of ‘Ganga Action Plan’ project, launched in 1985, was

1. A

   Make its water pollution free only

   Option (a) claims that the Ganga Action Plan launched in 1985 aimed to make the river water pollution free only. This is the key because the primary objective of this environmental initiative was pollution abatement, specifically improving water quality through interception, diversion, and treatment of domestic sewage.

2. B

   Utilize the river water for irrigation only

   Option (b) claims that the plan was meant to utilize river water for irrigation only. This is incorrect because irrigation was not the primary mandate of the Ganga Action Plan, which focused entirely on pollution control and water quality restoration.

3. C

   Build new dams over the Ganga river valley

   Option (c) claims that the project sought to build new dams over the Ganga river valley. This is incorrect as dam construction was never a part of the Ganga Action Plan, whose main thrust remained ecological restoration and pollution reduction.

4. D

   None of above

   Option (d) claims none of the above. This is incorrect because option (a) accurately states the primary pollution-reduction purpose of the 1985 Ganga Action Plan.

Summary. Official key is (a) Ganga Action Plan was launched in 1985 by the Ministry of Environment and Forests. Its primary objective was to improve the water quality of the river by preventing pollution. The project targeted domestic sewage and industrial waste entering the river course. Option (a) correctly captures this pollution-free mandate.