Suppose the Government Has Imposed a Price Floor on the Market

Suppose the government has imposed a price floor on the market for soybeans.Which of the following events could transform the price floor from one that is not binding into one that is binding?

A) Farmers use improved,draught-resistant seeds,which lowers the cost of growing soybeans.
B) The number of farmers selling soybeans decreases.
C) Consumers' income increases,and soybeans are a normal good.
D) The number of consumers buying soybeans increases.