Suppose That Two Types of Indistinguishable Coffee Beans Are Imported

Suppose that two types of indistinguishable coffee beans are imported to the U.S.: those grown in the mountains of South America and those grown in greenhouses in Canada.Mountain grown coffee produces a better tasting coffee,but buyers cannot distinguish the beans by sight or smell.Only the importers know the source of the beans.Buyers value mountain grown beans at $10 a pound and greenhouse grown beans at $3 a pound.Assume that 70% of imported beans are mountain grown,and 30% are greenhouse grown.
If a buyer offers $7 per pound,and the importer accepts the offer

A) the beans must be from Canada.
B) the beans must be mountain grown.
C) the beans may or may not be mountain grown.
D) both the buyer and the importer will gain surplus.