Ballast pump injection filter was cleaned and the pump was lined up. It was found that there was some leakage in the suction filter suction. The pump started and the leakage started. During de-blasting it was found that the pump could not take suction from one of the double bottoms. The cause could be

A) Pump was drawing air from.
B) Pump was drawing air from suction filter
C) One of the pipe lines on the suction side of the pump might be leaking
D) The filter was not cleaned properly.