How is a destress message normally initiated through INMARSAT?

A
All INMARSAT units have a dedicated key that can be pressed for immediate action.
B
By adding the word "DISTRESS" in the first line of the message's preamble
C
Certain INMARSAT units have a dedicated key that can be pressed for immediate action, while other systems provide menu-driven features.
D
By transmitting the distress message on the U.S. Coast Guard's dedicated monitoring channel.
E