Which of the following ways are suitable for increasing food producti…

The correct answer is Option (4) → All of these

I. The utilisation of improved crop varieties and agrochemicals can lead to increased crop yields. — True. This is agro-chemical based agriculture, the path of the Green Revolution. Yields rose partly because of improved crop varieties and mainly because of better management and agrochemicals (fertilisers and pesticides).

II. Employing manure, biofertilisers, biopesticides, and biocontrol agents is effective in augmenting crop production. — True. This is organic agriculture. Biofertilisers (bacteria, fungi and cyanobacteria) enrich the soil, and biocontrol agents control pests without harmful chemicals.

III. The adoption of genetically modified crops is a viable method to enhance crop production. — True. This is genetically engineered crop-based agriculture. GM crops, such as Bt cotton, can resist pests and stresses, so less of the crop is lost.

All three statements are the three options the book gives for increasing food production.

NCERT Extract:
Biotechnological Applications in Agriculture – “Let us take a look at the three options that can be thought for increasing food production (i) agro-chemical based agriculture; (ii) organic agriculture; and (iii) genetically engineered crop-based 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).”
Microbes as Biofertilisers – “… Of course, we have now realised that there are problems associated with the overuse of chemical fertilisers and there is a large pressure to switch to organic farming – the use of biofertilisers. Biofertilisers are organisms that enrich the nutrient quality of the soil.”