Task: Question Answering
Input (English): Background Paragraph: The classical explanation of gravity is that a force of attraction acts at a distance between two objects and the magnitude of the force is directly proportional to each of the masses and inversely proportional to the square of the distance between the objects. The objects move toward each other due to this force of attraction. Einstein’s new concept of gravity states that matter (mass) causes the space around the matter to curve and also distorts time. A straight line through this curved space would also be curved in order to be a straight line. 
Story: Rob is an amateur astronomer. Recently, he detected four asteroids, asteroid A, asteroid B, asteroid C, and asteroid D. Asteroid A and asteroid B are of the same mass, but asteroid A is farther from the earth than asteroid B. Asteroid C and asteroid D are at the same distance form the earth, but asteroid C has more mass than asteroid D. He also figured out that all of these asteroids have less mass than earth. 
Question: In clssical theory, if Rob needs to find out the object with stronger gravitational pull, which one would he choose, earth or asteroid A?
Output (English): earth.