The correct answer is (2) Herbicide resistance soybeans.

Most of the global transgenic crop area is planted with genetically modified soybean, predominantly engineered for herbicide tolerance (for example, glyphosate‑tolerant “Roundup Ready” types). These herbicide‑resistant soybeans occupy the largest share of worldwide GM crop hectarage, exceeding insect‑resistant cotton and other engineered traits.

Explanation of options

1. Insect resistance cotton

• Bt cotton (insect‑resistant cotton) is a major GM crop in countries like India, China, and the US, but its global planted area is smaller than that of herbicide‑tolerant soybeans.

• It is among the top GM crops but not the maximum worldwide.

2. Herbicide resistance soybeans – CORRECT

• Herbicide‑tolerant soybean is the single most widely grown GM crop globally, representing roughly half of all GM crop area in recent international reports.

• These soybeans allow broad‑spectrum herbicide use for efficient weed control, which drives their massive adoption.

3. Growing plants for desired molecules

• This refers to molecular farming or “biopharming” (plants engineered to produce pharmaceuticals, enzymes, or industrial compounds).

• Such crops are cultivated on relatively small, tightly regulated areas, far below staple GM commodity crops like soybean or maize.

4. Edible vaccines

• Edible vaccine plants (e.g., early experimental potato, banana, or tomato vaccines) are still largely at research or limited‑trial stages.

• They are not grown at commercial scale and contribute negligibly to global GM acreage.