Context: Isaac Newton was born in the 1600s and studied how objects move. He discovered three fundamental laws about forces and motion. According to Newton's third law, for every force, there is an equal and opposite force.
Consider the following force:
David is pulling on a full suitcase.
According to Newton's third law, what other force must be happening?
A. The suitcase is pulling on David.
B. The suitcase is pushing on David.
Identify the correct choice from the options below and respond with the letter of the correct option.

A