Indian farmers have very deep and extensive knowledge about the land…

The correct answer is Option (1) → They have been cultivating the land for centuries, much before the Green Revolution.

Option (1) They have been cultivating the land for centuries, much before the Green Revolution. — Correct. Indian farmers have tilled the land for centuries, long before the Green Revolution. This long experience is the source of their deep traditional knowledge of land and crops.

Option (2) Green Revolution programmes gave them access to new technology and know-how. — Incorrect. The Green Revolution brought new 'scientific' methods and hybrid seeds to farmers. Much of the farmers' traditional knowledge is in fact being lost as these seeds spread, so the programme cannot be its cause.

Option (3) The state promoted modern methods of cultivation in rural areas after Independence. — Incorrect. State support for modern methods came only after Independence. The farmers' knowledge is traditional and goes back many centuries before that.

Option (4) Farmers' movements have spread organic seeds and methods of cultivation among them. — Incorrect. Farmers' movements now suggest a return to traditional, organic seeds because of the harm done by modern methods. This call is recent, and the farmers had built up their knowledge over centuries before it.