UPSC Prelims 2023— Question 67

This question tests Wolbachia Method under Biotechnology. The central point is Wolbachia-based methods reduce transmission of mosquito-borne viruses. Option A: Controlling the viral diseases spread by mosquitoes. This is the keyed answer because it matches the governing fact or concept: Wolbachia-based methods reduce transmission of mosquito-borne viruses. Option B: Converting crop residues into packing material. This distractor is not the keyed answer because it conflicts with the specific factual relationship, chronology, institutional role, geographic association or conceptual distinction tested in the question. Option C: Producing biodegradable plastics. This distractor is not the keyed answer because it conflicts with the specific factual relationship, chronology, institutional role, geographic association or conceptual distinction tested in the question. Option D: Producing biochar from thermo-chemical conversion of biomass. This distractor is not the keyed answer because it conflicts with the specific factual relationship, chronology, institutional role, geographic association or conceptual distinction tested in the question. The question should be approached by checking each statement independently rather than accepting a familiar phrase at face value. This is particularly important in UPSC questions where a single incorrect institutional attribution, location, chronology, absolute word or causal link can invalidate an otherwise plausible option. The broader revision takeaway is to connect the keyed answer with the underlying concept rather than memorizing only the letter. The options also illustrate how UPSC constructs distractors by mixing correct facts with one altered detail. In revision, candidates should therefore retain both the positive fact and the nearest contrasting fact so that the same concept can be recognized when the framing changes in another year.