How much work would be needed to raise the payload from the surface of the moon (i. e., x = r) to an altitude of 5r miles above the surface of the moon (i. e., x = 6r)?

Let the data is as following

mass of payload = "m"

mass of Moon = "M"

now we know that we place the payload from the position on the surface of moon to the position of 5r from the surface

So in this case we can say that change in the gravitational potential energy is equal to the work done to move the mass from one position to other

so it is given by

we know that

now from above formula

so above is the work done to move the mass from surface to given altitude

i am pretty sure it is c because when people are closer together, they cannot move as freely. picture being in a mostly full elevator, for instance. the people are right next to you, and you can barely move.