The Reason an Astronaut in an Earth Satellite Feels Weightless

The reason an astronaut in an earth satellite feels weightless is that

A) the astronaut is at a point in space where the effects of the moon's gravity and the earth's gravity cancel.
B) this is a psychological effect associated with rapid motion.
C) the astronaut is falling.
D) the astronaut is beyond the range of the earth's gravity.
E) the astronaut's acceleration is zero.