The key factors to consider when approaching a casualty vessel or survivors are（）1.If a lee side protection is require。2.The rate of drift of the casualty vessel or survivors.3.The rate of drift of the rescue vessel.

A.1 and 2 only

B.2 and 3 only

C.1 and 3 only

D.1，2 and 3

正确答案：1，2 and 3