Final answer:
Rugby wheelchairs require more force to start moving or stop.
Step-by-step explanation:
In order to get a heavier wheelchair to start moving or stop, the player must apply more force.
According to Newton's First Law of Motion, an object at rest will stay at rest and an object in motion will stay in motion with the same speed and direction unless acted upon by an external force. The force applied by the player overcomes the inertia of the wheelchair and changes its motion.
Therefore, the correct answer is A. Force.