What Does the Equivalence Principle Say

What does the equivalence principle say?

A) Gravity is the same thing as curvature of spacetime.
B) The effects of gravity are exactly equivalent to the effects of acceleration.
C) You cannot distinguish between motion at constant velocity and weight in a gravitational field.
D) The effects of relativity are exactly equivalent to those predicted by Newton's laws of motion.
E) All observers must always measure the same (equivalent) weights for moving objects.