The word to fill in the blank is "equal". Because the time taken to rotate (spin on its axis) is equal to the time of revolution (going around the earth), this means that both have the same rate of angular rotation. So for every bit that the moon goes around its orbit around earth, the moon itself rotates accordingly to present the exact same side to earth.
If someone is underground, then therefore there is less planet/ground underneath them, so there would be less gravity. Gravity directly affects weight.
We know, Potential Energy = Force * Height
Here, F = 40 N
h = 5 m
Substitute their values,
U = 40 * 5
U = 200 J
In short, Your Answer would be Option A
Hope this helps!
