Class I and II private aids to navigation in or along navigable waters of the United States are listed in the（）.

A.radio time signal
B.comparison with a timepiece of known error
C.applying the prevailing chronometer rate to previous readings
D.All of the above

A.National Geospatial-Intelligence Agency
B.Coast Guard
C.Naval Observatory
D.National Ocean Service

A.underlined letters
B.capital letters
C.italics
D.boldface print