What is the common initial shape of a valley formed by a river?

Correct answer: V-shaped valley

The correct answer is A, a V-shaped valley. In the upper course of a river, the land slope is usually steep and the river has strong downward, or vertical, erosion. It cuts the river bed more deeply than it widens the sides. The valley therefore begins as a narrow depression with sloping sides that meet in a V-like cross-section. Option B is incorrect because a U-shaped valley is mainly associated with the broad erosional action of a glacier. Option C is a mound, not a river valley. Option D is a wind-deposited sand landform. Remember the simple contrast: youthful rivers commonly cut V-shaped valleys, whereas glaciers commonly create U-shaped valleys.