PE = 0.5 × k × x²
PE potential Energy
k spring constant
x stretch/compression of the spring
I'd say A. because an inference is a guess/estimate. You can assume that the egg rolled off the kitchen but you know that C and D are true.
Ground water keept the ground at a stable level when it is gone the cavern it was in has no support and is at risk of callaps
D is the best answer. In many physics problems we treat an extended object as if it were a point with the same mass located at the center of mass.