While loading bunkers, you notice oil on the water near the vesselWhat should you do first

While loading bunkers, you notice oil on the water near the vesselWhat should you do first？

A.Stop loading

B.Notify the harbour administration

C.Determine if the vessel is the source of the pollution

D.Start the main engine and put them in gear to disperse the spill

请帮忙给出正确答案和分析，谢谢！