Why is a book resting on a table in a state of equilibrium?

A. The book and the table have the same weight
B. Gravity is a net force acting on the book in a downward direction
C. The books weight and the upward force the table exerts on the book have equal magnitude but opposing directions
D. The book and the table both have acceleration (due to gravity) of 9.8 m/s/s

C. The book's weight and the upward force the table exerts on the book have equal magnitude but opposing directions.