Shaktiman-I and Shaktiman-II are the genetically modified crops of:

Cotton
Rice
Maize
Wheat

The correct answer is (a), cotton.

Shaktiman-I and Shaktiman-II are genetically modified cotton varieties that are resistant to the bollworm pest. They were developed by the Central Institute for Cotton Research (CICR) in India. Shaktiman-I was released in 1998, and Shaktiman-II was released in 2002. Both varieties have been widely adopted by farmers in India.

Cotton is a major cash crop in India, and the bollworm is a major pest of cotton. The bollworm attacks the cotton boll, which is the fruit of the cotton plant. The bollworm larvae feed on the cotton fibers, which can cause significant damage to the crop.

Shaktiman-I and Shaktiman-II are resistant to the bollworm because they have been genetically modified with a gene from the bacterium Bacillus thuringiensis (Bt). Bt produces a protein that is toxic to the bollworm. When the bollworm larvae eat the cotton fibers, they ingest the Bt protein and die.

Shaktiman-I and Shaktiman-II have been shown to be effective in controlling the bollworm pest. They have also been shown to be safe for human consumption and the environment.

The other options are incorrect because they are not crops that are resistant to the bollworm pest.