When latitude and longitude are used，these shall be expressed in（）（and decimals of a minute if necessary），north or south of the Equator and east or west of Greenwich.

A.A current at minimum flow
B.A current coming in
C.A current going out
D.A current at maximum flow

A.A spherical topmark
B.Red and white retroreflective material
C.A sequential number
D.A red and white octagon

A.Horizontal movement of the water toward the land after high tide
B.Horizontal movement of the water toward the land after low tide
C.Horizontal movement of the water away from the land following high tide
D.Horizontal movement of the water away from the land following low tide