Concept:Newton's third law of motion states that action and reaction forces are equal in magnitude and opposite in direction.
Explanation:The towing vehicle and the bus exert forces on each other. These form an action–reaction pair.
By Newton's third law, the force exerted on the bus by the towing vehicle is equal in magnitude to the force exerted on the towing vehicle by the bus.
Therefore, statement II is correct.
Statement I compares a force between vehicle and bus with a force between bus and road, so it is not an action–reaction pair.
Statement III is false because it contradicts Newton's third law.
Statement IV is also not a direct action–reaction pair and is not generally true.
Hence, only statement II is correct.
Answer:B. II only