UPSC Prelims 2020— Question 2

This question tests drone applications. The key concept is: Modern drones can spray agricultural inputs, survey hazardous volcanic terrain and collect biological samples such as whale blow for research. Their value is that they can carry sensors or payloads into places that are dangerous, remote or difficult for people to access. The verified answer for the uploaded Set-B paper is option D. Option A — 1 and 2 only: This is not the correct option. The option does not match the verified combination or conclusion. The decisive point is the distinction explained above: Modern drones can spray agricultural inputs, survey hazardous volcanic terrain and collect biological samples such as whale blow for research. Their value is that they can carry sensors or payloads into places that are dangerous, remote or difficult for people to access. Therefore this alternative should be eliminated even if part of its wording appears plausible in isolation. Option B — 2 and 3 only: This is not the correct option. The option does not match the verified combination or conclusion. The decisive point is the distinction explained above: Modern drones can spray agricultural inputs, survey hazardous volcanic terrain and collect biological samples such as whale blow for research. Their value is that they can carry sensors or payloads into places that are dangerous, remote or difficult for people to access. Therefore this alternative should be eliminated even if part of its wording appears plausible in isolation. Option C — 1 and 3 only: This is not the correct option. The option does not match the verified combination or conclusion. The decisive point is the distinction explained above: Modern drones can spray agricultural inputs, survey hazardous volcanic terrain and collect biological samples such as whale blow for research. Their value is that they can carry sensors or payloads into places that are dangerous, remote or difficult for people to access. Therefore this alternative should be eliminated even if part of its wording appears plausible in isolation. Option D — 1, 2 and 3: This is the correct option. It matches the verified conclusion because Modern drones can spray agricultural inputs, survey hazardous volcanic terrain and collect biological samples such as whale blow for research. Their value is that they can carry sensors or payloads into places that are dangerous, remote or difficult for people to access. The wording of the option is consistent with the governing concept tested by the question. For UPSC-style elimination, first identify the exact proposition being tested, then evaluate each statement independently before comparing the answer codes. Avoid treating a broad or absolute statement as correct merely because its general theme is familiar. The precise qualifiers in the question—such as 'all', 'only', 'cannot', 'largest', 'always' or a specific institutional role—often determine the answer. On that basis, option D is the verified answer.