Which is the correct sequence of river work in upper and lower courses of a Himalayan river?

Correct answer: Erosion upstream and deposition downstream

Direct answer: Option B is correct. A Himalayan river normally has a steep upper course and a gentler lower course. In the upper course, the slope and velocity are high, so vertical erosion, valley cutting and gorge formation are important. In the lower course, the slope becomes gentle, the river loses much of its transporting power, and deposition of sediment becomes more important. Step by step: steep slope gives greater energy; greater energy causes strong upstream erosion; downstream slope decreases; transporting power falls; sediments are deposited. Option A reverses the usual pattern, so it is wrong. Option B correctly states erosion upstream and deposition downstream. Option C is wrong because rivers do not form glaciers in both courses; glaciers are formed by long-term accumulation and compaction of snow in cold regions. Option D is wrong because rivers actively erode, transport and deposit material. Exam cue: upper course—erosion; lower course—deposition, though real rivers may show overlapping processes.