Given:
Valerie drives 400 meters up a hill that makes an angle of 20° with the horizontal.
To find:
The horizontal distance she has covered.
Solution:
The figure showing the scenario is as follows:
Let the horizontal distance traveled be x meters.
The horizontal distance traveled can be obtained using the trigonometric function cosine.
In the figure,

Thus, the horizontal distance covered is 375.9 ft.
Thus, option B is correct.