You are a watch standing mate and have come to the bridge to relieve the watch. After reviewing the chart and having been briefed by the off-going mate，you are now ready to effect the relief. The watch is officially transferred to you after ______.
A.you state the vessel's charted position，present course and port of destination
B.the mate being relieved tells you the vessel's course and speed and states that you have the watch
C.you say，"I relieve you" and you state the course per gyro and magnetic compasses
D.the mate being relieved says，"You have the conn" and you state the ship's course
正确答案是C