An astronaut, floating alone in outer space, throws a baseball. If the ball floats away at a speed of 20 meters per second, the astronaut will
a) move in the opposite direction at a speed of 20 m/s.
B. move in the opposite direction, but at a lower speed.
C. move in the opposite direction but at a higher speed.
D. stay still.
E. move in the same direction as the baseball.
