Question

18.

Answer 1

The most prominent features of a narrow, V-shaped valley, where the stream profile drops rapidly, are rapids and waterfalls. The correct option among all the options that are given in the question is the second option. I hope that this is the answer that you were looking for and the answer has come to your help.

Answer 2

The correct answer is rapids and waterfalls.  

Rapids refers to the segments of streams with extensively vigorous currents, various obstacles, and steps in their streambeds. A waterfall refers to a vertical drop in a stream bed. Both are the locations of vigorous erosion.  

The rapids are generally produced where the resilient bedrock limits a stream to a narrow channel and forces an enhancement in the velocity of water.  

On the other hand, waterfalls are produced where the fast-flowing water negotiates a geologic contact amid the more resilient and less resistant layers of rock, or through a fault, which has analogized distinct kinds of rocks. Or it can be said that waterfalls usually produce at the end of a series of rapids.