Answer: Â [A]: Â "a decrease in the number of producers" .
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 Note:  The "consumers" tend to be more mobile (at all levels) compared to the  the "producers"—which are less "mobile"— (plants, grass, trees, moss, other autotrophs); as such, the "producers" will have the greatest tendency to decrease to due destruction (as the most immediate effect—considering the answer choices given).
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