Final answer:
The force that moves a boat when someone rows it is caused by the interaction between the oars and the water. Fins, paddles, and motors also provide the force to move the boat forward. The correct option is A.
Step-by-step explanation:
When someone rows a boat using oars, the force that moves the boat forward is caused by the interaction between the oars and the water the boat is traveling in. This interaction creates a push against the water, propelling the boat forward. The rower's arms provide the force that is transmitted to the oars, which in turn transmit the force to the water.
When using fins, the force that moves the boat forward is caused by the interaction between the fins and the water. Fins create a force called drag, which is a resistance force that propels the boat forward.
When using paddles, the force that moves the boat forward is also caused by the interaction between the paddles and the water. Similar to oars, paddles create a push against the water, propelling the boat forward.
When using motors, the force that moves the boat forward is caused by the power generated by the motor. The motor converts energy (e.g. fuel or electricity) into mechanical energy, which drives the boat forward.