046E D
 The USA-INT control on VHF units:
a) Was made necessary by a desire for more simplex channels in the U.S.
b) Correctly set, will result in duplex operations in U.S. Coastal waters on the "alpha" channels.
c) Correctly set, will result in simplex operations in U.S. Coastal waters on the "alpha" channels.
d) Both a) and c) are true
