【单选题】A crew member reports that the high-pressure alarm light of a low-pressure CO2 fixed fire extinguishing system is illuminated.The most probable cause of this condition would be that ______.
A.
an air leak has developed in the tank
B.
the tank cooling system has malfunctioned
C.
the pilot cylinder discharge valve is leaking
D.
an excessive amount of insulation has been installed on the tank and piping