If a river has steep slope in upper course and gentle slope in lower course, how will river work change?

Correct answer: Erosion will dominate upstream and deposition downstream

Direct answer: C, erosion dominates upstream and deposition is greater downstream. A river’s work depends strongly on gradient, speed, discharge, and sediment load. In the upper course, the steep slope gives the river more energy, so it cuts downward and sideways and transports rock fragments. In the lower course, the gentle slope reduces velocity; the river cannot carry all its load, so it deposits sediment on the bed, banks, floodplain, or delta. Option A is wrong because vertical erosion is not the only downstream process. Option B reverses the expected pattern: gorges are linked mainly with strong upper-course erosion, not ordinary gentle-slope downstream work. Option C is correct. Option D is wrong because river action does not stop. Memory cue: steep slope cuts; gentle slope deposits.