UPSC Prelims 2015— Question 30

Correct answer: Option D. IceCube is a large neutrino detector embedded deep in the Antarctic ice at the South Pole. It instruments roughly a cubic kilometre of ice to detect neutrinos through the secondary charged particles they produce. Its scientific programme includes high-energy neutrino astronomy and studies relevant to astrophysics; it is also used in searches related to dark matter. Thus all three statements are correct. Option-wise analysis: Option A: “1 only” is incorrect. It does not match the specific fact, definition, institutional role, geographical association, or constitutional/economic principle required here. The key distinction is the one identified in the core explanation, so this option can be eliminated. Option B: “2 and 3 only” is incorrect. It does not match the specific fact, definition, institutional role, geographical association, or constitutional/economic principle required here. The key distinction is the one identified in the core explanation, so this option can be eliminated. Option C: “1 and 3 only” is incorrect. It does not match the specific fact, definition, institutional role, geographical association, or constitutional/economic principle required here. The key distinction is the one identified in the core explanation, so this option can be eliminated. Option D: “1, 2 and 3” is correct. It directly matches the factual or conceptual requirement tested by the question and is supported by the principle explained above. Prelims takeaway: Focus on the precise institutional role, constitutional provision, geographical association, or technical definition being tested. UPSC questions often place a broadly familiar fact beside a narrowly incorrect qualifier; identifying that qualifier is essential for elimination.