When APU master switch is OFF, when will be APU normally shut down?

A、APUcoolsdownfromtheoperationfor100s,andthencontinuestooperatefor15s,andAPUisshutdown.
B、APUcoolsdownfromtheoperationfor105s,andthencontinuestooperatefor15s,andAPUisshutdown.
C、AfterAPUcontinuestooperateat100%RPMfor100secondstocooldown,APUisshutdown
D、AfterAPUcontinuestooperateat100%RPMfor105secondstocooldown,APUisshutdown