If there is an excess demand for corn:

a. corn producers will reduce output and sales will fall.

b. corn prices will tend to fall.

c. corn prices will tend to increase.

d. the price of corn must be above the equilibrium price.

The correct answer is: c. corn prices will tend to increase.

When there is an excess in demand of corn in the corn market, it implies the situation that the quantity of product demanded is more significant that that of supplied. Hence, it results in the shortage in the market. During shortage, the price of corn will be lower than the equilibrium price, which leads to the increase in corn prices to offset the shortage.

Particularly, when the corn prices increase, the demand declines, meanwhile, to attain a greater profit, the suppliers have incentives to boost the supply. Until the new equilibrium price level is attained, this practice ends.