单项选择题
A.state of wind，sea，and current，and the proximity of navigational hazards
B.maximum attainable speed of your vessel
C.temperature
D.aids to navigation that are available
单项选择题 The Rules state that certain factors are to be taken into account when determining safe speed. One of the factors is the（）.
单项选择题 The rules require that a stand-on vessel SHALL take action to avoid collision when she determines that（）.
单项选择题 The risk of collision shall be deemed to exist if the compass bearing of an approaching vessel （）.