A Farmer Decides to Let a Field That Has Been

A farmer decides to let a field that has been under cultivation revert back to natural prairie.The field is surrounded by other agricultural crop fields.The developing prairie may receive input of species from all of the following sources except

A) seeds carried in on animal fur.
B) seeds brought in by birds from the area.
C) seeds brought in by wind and rain.
D) species living outside the regional species pool.
E) small mammals moving in from nearby fields or edges.