Statement I: The Green Revolution increased food production primarily…

The correct answer is Option (3) → Both statements I and II are correct.

Food production has been raised by different routes: the Green Revolution, organic agriculture and genetically engineered crops.

Statement I: The Green Revolution increased food production primarily through the use of agrochemicals and improved management practices. — True. The Green Revolution tripled the food supply. The higher yields came partly from improved crop varieties but mainly from better management practices and agrochemicals (fertilisers and pesticides). “Primarily” in the statement matches the book's “mainly”.

Statement II: Bt cotton is an example of a genetically modified crop that incorporates a gene from Bacillus thuringiensis to produce a protein toxic to insects. — True. The Bt toxin gene was cloned from the bacterium and expressed in cotton. The plant makes the toxin itself and resists insects without insecticides, so it works as a bio-pesticide.

NCERT Extract:
Biotechnological Applications in Agriculture – “… The Green Revolution succeeded in tripling the food supply but yet it was not enough to feed the growing human population. Increased yields have partly been due to the use of improved crop varieties, but mainly due to the use of better management practices and use of agrochemicals (fertilisers and pesticides).”
Biotechnological Applications in Agriculture – “… Bt toxin is produced by a bacterium called Bacillus thuringiensis (Bt for short). Bt toxin gene has been cloned from the bacteria and been expressed in plants to provide resistance to insects without the need for insecticides; in effect created a bio-pesticide. Examples are Bt cotton, Bt corn, rice, tomato, potato and soyabean etc.”