To Test Whether the Law of Demand Holds Using Calculus

Multiple Choice

To test whether the law of demand holds using calculus, you should:

A) take the partial derivative of quantity demanded Q^D with respect to P and conclude that the law of demand holds if this derivative is positive at the market price.
B) take the partial derivative of quantity demanded Q^D with respect to P and conclude that the law of demand holds if this derivative is negative at the market price.
C) take the derivative of P with respect to quantity demanded Q^D and conclude that the law of demand holds if this derivative is positive at the market price.
D) take the derivative of P with respect to quantity demanded Q^D and conclude that the law of demand holds if this derivative is negative at the market price.