For GMDSS, when may a compulsory vessel not be allowed to leave port?

A
When the vessel is in an overloaded condition
B
When the vessel has arranged for both duplication of equipment AND shore-based maintenance
C
When the vessel has replaced a required piece of GMDSS-related equipment but its performance has not been verified or logged
D
When the vessel is carrying only two licensed GMDSS Radio Operators and is capable of performing all required functions
E