Which of the Following Statements Is Correct

Multiple Choice

Which of the following statements is correct?

A) The use of pollution permits and corrective taxes reduces the cost of environmental protection.
B) Rich countries usually have cleaner environments than poor countries because a clean environment is like other normal goods in that it has a positive income elasticity.
C) Clean water and clean air are goods to which the law of demand applies.
D) All of the above are correct.