David Tilman and colleagues examined the influence of community diversity on aboveground biomass (i.e. productivity) over seven years (only five years are shown). What might explain the variation in productivity among years? Question 11Select one: A. Monocultures likely achieved lower productivity or carbon stores than higher-diversity sites. B. Interannual weather variability likely caused productivity to vary. C. Community productivity and drought tolerance likely increased over time. D. Community productivity and diversity likely increased over time