Answer: a. net force is acting on object A in the same direction of its motion.
Step-by-step explanation:
The second law of Newton states that the acceleration of a particular object is dependent on two main things which are the mass and force. According to the law, the acceleration of the object will be directly related to the net force while the acceleration is also relates inversely to the mass.
Therefore, based on the information given in the question, a force is acting on object A in the same direction of its motion.