You are on international waters during a heavy ra

You are on international waters during a heavy rainstorm and hear a vessel sounding a fog signal of one prolonged blast followed by two short blasts． Which of the following could it be？Ⅰ．A vessel laying submarine cable making way．Ⅱ．A pilot vessel on station at anchor．

A.Ⅰ only

B.Ⅱ only

C.Either Ⅰ or Ⅱ

D.Neither Ⅰ nor Ⅱ

请帮忙给出正确答案和分析，谢谢！