If You Drop Your Textbook, It Falls Because the Earth

Multiple Choice

If you drop your textbook, it falls because the earth pulls it downward. At the same time, your textbook pulls on the earth with a force that is

A) equal to the downward pull on the textbook and in the same direction.
B) equal to the downward pull on the textbook but in the opposite direction.
C) immeasurably small.
D) zero.