What would be the most probable cause for a high pressure alarm to be activated in a Low Pressure CO2 fixed fire extinguishing system?

Correct Answer: Option C — The tank cooling system has malfunctioned.

Low-pressure CO2 systems store liquid carbon dioxide at approximately 0°F (-18°C) using a refrigeration unit. If the cooling system fails, the liquid warms, causing the pressure to rise rapidly. This triggers the high-pressure alarm, alerting the crew to a potential system failure that could lead to an unintended discharge.