The above figure illustrates the market for corn. If point "a" represents the original equilibrium and point "b" the new equilibrium, which of the following could have caused the change? Price (dollars per bushel of corn) a b S a decrease in the input cost of production an increase in labor costs of producing corn D Quantity (millions of bushels of corn per year) an increase in consumers' preferences for corn S2 a severe drought causes negative impact on the production