The duties of the look-out and helmsperson are separate and the helmsperson shall not be considered to be the look-out while-steering, except _______. '
A.it has been established without doubt that it is safe to do so
B.the situation has been carefully assessed
C.full account has been taken of all relevant factors
D.in small ships where an unobstructed all round view is provided at the steering position and there is no impairment such as night vision or other impediment to the keeping of a proper look-out
正确答案是D