Control of river flow by lakes is most possible due to which reason?

Correct answer: Lakes have the capacity to hold and release water

The direct answer is A, lakes have the capacity to hold and release water. A lake acts like a temporary natural storage basin. Step by step: rain or river water enters the lake; the lake stores part of this water; during heavy flow it can reduce the sudden movement of water, and later water may flow out gradually or support the river. This is why lakes can regulate river flow and sometimes reduce floods or maintain flow in drier periods. Option A is correct because storage and controlled release are the relevant reasons. Option B, lakes always raising the river bed, is not a general function and does not explain regulation. Option C, making all rivers underground, is factually false. Option D, permanently stopping clouds, is impossible and unrelated to river-flow control. The exact effect depends on the lake, its outlet and local conditions, so “control” does not mean complete control. Memory cue: a lake is a water buffer—store now, release later.