The type of pump circulation system is

Here’s why in simple terms:

1. It's not an "Open System":

Automobile cooling systems are closed systems—they're sealed to prevent coolant loss and contamination. In an open system, the coolant would be exposed to the air, which isn’t the case here.

2. It's not technically a "High Pressure System":

While the system is pressurized, it doesn’t qualify as a “high pressure system” in the typical engineering sense. The pressure is only slightly elevated to raise the boiling point of the coolant and improve heat transfer—not enough to be classified as "high pressure" like in hydraulics or steam systems.

3. So, “None of these” is the most accurate label:

The cooling system is best described as a closed, pump-driven circulation system, which isn’t covered by the options A or B.

Final Answer: Option D: None of these