Answer:
B). action and reaction forces
Step-by-step explanation:
This is a consequence of Newton's third law, which states:
"When an object A exerts a force on an object B, then object B exerts an equal and opposite force on object A. These two forces are called action and reaction"
In this case, we can think the force exerted by the person on the raft as the action, and the force exerted by the raft on the person as the reaction. According to Newton's third law, these two forces are exerted into opposite directions: therefore, the person will be pushed in one direction, while the raft will be pushed in the opposite direction. This is why the two objects move into opposite directions.