The correct answer is [A] The specific heat of water is high. Water’s high specific heat allows it to absorb a significant amount of heat from the engine, effectively cooling it. This property makes water an efficient coolant for radiators in motor vehicles, helping to maintain engine temperatures within safe operating limits. Additionally, water is readily available and cost-effective, contributing to its widespread use as a coolant. While its density and availability at low temperatures may also play a role in its utility as a coolant, it is primarily the high specific heat capacity of water that makes it an ideal choice for cooling engines, ensuring optimal performance and preventing overheating.