What is not the possible reason for the increasing fish stocks by trawling
A.Trawling stirs up the seabed and leaves potential food into the water.
B.Discards from trawling make more food available on the sea floor.
C.Trawling can stimulate fisheries because of drifting from ecosystems.
D.Trawling makes seabed be more flat and featureless, which is beneficial for fish survive.