046D B
 The USA-INT control on VHF units:
a) Selects duplex operations for U.S. coastal waters and simplex operations in non-U.S. waters, on the "alpha" channels.
b) Changes selected international duplex channels to simplex channels for use in U.S. waters.  
c) Both of the scenarios above may be set up and selected by the operator.
d) None of the above
