Ed sells wheat in a perfectly competitive market. There has been a dramatic increase in the number of people who are allergic to gluten (which is found in wheat). Because Ed operates a profit-maximizing farm, how will he react to this change in the market for wheat?

a. He will decrease output because the marginal revenue curve shifts downwards.

b. He will not react because its demand curve is perfectly elastic.

c. He will increase output because some firms will leave the industry

d. He will increase output because the marginal revenue curve shifts upwards