Explanation
- A
Only one
Only one. All three ‘no virus can…’ lines are false.
- B
Only two
Only two. There is no correct pair here.
- C
All the three
All three. Viruses do survive in oceans, infect bacteria (bacteriophages), and alter host transcription.
- D
None
None. Each absolute ‘no virus can’ claim fails.
Summary. Official Set A key is (d) none. Oceans are full of viruses. Bacteriophages infect bacteria. Viruses routinely hijack host transcription. I, II and III are all false universals. The official count of correct statements is zero.
Same topic · past papers
UPSC has asked this before
These previous-year questions sit on the same topic. Open one to practise the earlier ask.