The phrase "winnow out" in the second paragraph is closest in meaning to" __________."

A．Because it caused environmental pollution and didn't really benefit the budget.
B．Because the businessman turned mayor was persuaded by contractors to do so.
C．A new method was found to recycle the plastic in a cheaper way.
D．The new mayor of the city regards recycling as necessary.

A．Miguel, a trashman, is confused with what he should do for his job.
B．The New York City government is not a responsible government.
C．It takes long time and efforts to make a rational policy.
D．Constant changes of the recycling policy in New York City lead to confusion.