Answer:
D. 914 feet
Step-by-step explanation:
We are given the distance that a person can see on a clear day from the upper observation platform of the Eiffel tower in Paris. We are then required to estimate the height of the upper observation platform using the formula;

Where d is the distance and h the height of the upper observation platform. The first step would be to solve for h, that is make h the subject of the formula in the above equation;
We multiply both sides of the equation by the reciprocal of 5/6 which is 6/5;

The next step is to eliminate the square root on the Left Hand Side of the equation by squaring both sides;

Given d is 25.2, h becomes;

To the nearest whole number, h becomes 914