If you were to examine the longitudinal profile of a typical river, you would probably find that the gradient is .

steepest near the headwaters.

Explanation:

Stream Gradient is the slope-drop over distance. Stream gradient can be defined as a drop of stream in vertical line and falling over a horizontal distance.

The steam gradient, if we examine the longitudinal profile of a typical water, will be steepest near the headwaters. The stream gradient is steepest near the headwaters whereas gentle at the mouth. After the stream reaches at the mouth it gets discharged into another water body.

So, the correct answer is that the stream gradient is steepest near the headwaters.