Which of the Following Is Correct with Respect to the Issue

Multiple Choice

Which of the following is correct with respect to the issue of supply and demand?

A) A demand curve shows that consumers usually demand products of higher quality.
B) A supply curve shows that businesses will supply more units of a product, but will lower the level of product quality.
C) It is difficult to achieve an equilibrium price.
D) When the quantity demanded exceeds the amount supplied, businesses shut down.
E) None of the statements are correct.