Look at the graph. Does zone A represent the result of a price ceiling or price floor, and which scenario is an example of these conditions?
O A price ceiling and the excess butter sitting in European warehouses due to overproduction by farmers
O A price ceiling and the scarcity of food and other goods in Cuba, resulting in smuggling and black-market trading
O A price floor and the lack of construction materials in Venezuela due to exporting them for higher prices
O A price floor and the large amount of corn stored in silos in the U.S. Midwest due to overproduction by farmers