In which process does rock weaken at its own place?

Correct answer: Weathering

The direct answer is A, Weathering. Weathering means the breaking down or weakening of rock at the place where the rock is found. It does not require the broken material to be carried away. Step by step: first, rain, heat, cold, chemicals, plant roots, or animals act on exposed rock; next, the rock becomes cracked, weak, or chemically changed; finally, the material may remain there until erosion transports it. Option A is correct because weathering is an in-place process. Option B, river transportation, is wrong because a river carries sediment from one place to another; it is movement, not weakening at the original place. Option C, marine deposition, is wrong because deposition means sediments settle in a sea or coastal area. Option D, glacial accumulation, is wrong because accumulation means material is collected or deposited by a glacier. A useful memory cue is: weathering works where the rock is, while erosion transports what weathering produces.