The pressure difference of the gauge on the oily water separator increases greatly, the re

The pressure difference of the gauge on the oily water separator increases greatly, the reason is____.

A.the filter is clogged

B.bilge suction value is clogged

C.suction value and discharge value of the pump do not open fully

D.screw pump is worn seriously and volumetric efficiency is decreased

请帮忙给出正确答案和分析，谢谢！