Answer: The estimate is closest to the distance d is 4.2 miles
Explanation:
In the given image, we can see that there is a right triangle, in which d is the side opposite to the right angle (largest angle in the triangle) which means its the longest side of the triangle.
[Since side opposite to the larger angle is larger]
Therefore, by Pythagoras Theorem we have

The estimate is closest to the distance d is 4.2 miles.