UPSC Prelims 2018— Question 82

**Concept and analysis:** Organic matter generally improves soil structure and water-holding capacity, so the first statement is the opposite of the usual relationship. Soil microorganisms and chemical processes are important components of the sulphur cycle, so the second statement is also false. Irrigation in poorly drained or arid areas can cause salts to accumulate in the root zone through evaporation and inadequate drainage, making the third statement correct. The question is testing precise UPSC-level identification rather than a broad association. The key is to distinguish the exact institutional, constitutional, historical, geographical, economic or scientific feature being asked. **Option-wise evaluation** **Option A:** Incorrect. It selects 1 and 2 only, but that combination does not match the verified statement-level assessment; it either includes a false statement or omits a true one. **Option B:** Correct. It selects statements 3; these are the statements supported by the relevant constitutional, economic, historical, scientific or geographical facts. **Option C:** Incorrect. It selects 1 and 3 only, but that combination does not match the verified statement-level assessment; it either includes a false statement or omits a true one. **Option D:** Incorrect. It selects 1, 2 and 3, but that combination does not match the verified statement-level assessment; it either includes a false statement or omits a true one. **UPSC takeaway:** The safest way to solve this type of question is to anchor the answer in the defining feature of the concept and then test every option against that feature. Closely related institutions or terms are often used as distractors. In statement-based questions, do not judge the option as a whole before checking each statement independently. In factual questions, compare the wording of each option with the exact definition, location, institutional role, chronology or scientific property. The correct answer follows from that verification rather than from familiarity with a keyword.