How does an icebreaker normally free a ship which has become beset while navigating independently?（）
- ABy backing down the track and cutting out ice on either bow
- BBy approaching from the stern and crossing ahead at an angle of 20°to 30°to the beset ship's course
- CBy overtaking the beset ship，running ahead and then backing down the track to the beset vessel
- DBy approaching the vessel from astern and towing the beset vessel stern first