Hi Tanuj,

I am no expert but could help you with this one. Hope you find it useful.

Before we evaluate the options, its important to know what gravitational compensation refers to.
Gravitation compensation refers to the phenomena of achieving positive gravity even when a hole or deficit of mass exists.

Now, Lets evaluate the options:

a. Describes why gravitation anomaly is caused. So incorrect.
b. Passage no where says that the impactor leaves debris. However, passage suggests that debris is ejected FROM MOON'S SURFACE when an impactor strikes.So out of scope.
c. Describes why gravitation compensation could not occur. So incorrect.
d. Similar to A. So incorrect.
e. Describes why gravitation is not negative despite debris ejection. Correct.

Hope it helps.