Risk of collision is considered to exist if _________.

A、Risk of collision is considered to exist if _________.
B、Risk of collision is considered to exist if _________.
C、Risk of collision is considered to exist if _________.
D、Risk of collision is considered to exist if _________.
E、Risk of collision is considered to exist if _________.
F、Risk of collision is considered to exist if _________.
G:Risk of collision is considered to exist if _________.
H:Risk of collision is considered to exist if _________.