Those who are opposed to GMOs say that.
The correct answer to complete the sentence is Option D.
The passage mainly speaks about GMO (Genetically Modified Organisms), and its effects if consumed by humans. While one section of the people say that genetic techniques are helping the food industry, the others, specially the food safety people, say otherwise.
The later part of the passage speaks about people who are opposed to the idea of GMO being mixed into the food, as it involves serious health risks including cancer. In a situation, which causes and spreads illness, the latter section of the society is arguing for a healthier option as mentioned in Option D.
The other options, A, B and C, talk about the costs of the crops, the pattern of the crops and crop research, which is not explained in the passage, hence eliminating the same.