Which One of the Following Observations Was Not an Outcome

Multiple Choice

Which one of the following observations was not an outcome of studies by David Tilman and coworkers at Cedar Creek,Minnesota on ecosystem stability?

A) Plots with more species showed less year-to-year variation in biomass.
B) Species rich plots were less affected by drought than species poor plots.
C) More diverse plots were less susceptible to invasion by new species.
D) Nitrogen uptake and total biomass produced were negatively correlated to species richness.
E) Overyielding was observed in more recent work at Cedar Creek.