GMDSS. FCC Test 49

What is meant by the term 'ITU channel'?
Which statement regarding channel spacing and bandwidth is true?
Which statement regarding bandwidth and channel spacing is correct:
Which of the following is a valid 22-MHz ITU Channel?
The proper sequence of channel spacing from narrow to widest is:
The purpose of ITU channel spacing is:
Which is a valid ITU Designation?
ITU channels are:
ITU channel 1604 would mean:
Which of the following defines 'ITU Channel 1216'?