Which of the Following Is Not One of the Reasons

Multiple Choice

Which of the following is not one of the reasons why it is difficult to empirically test alternative macroeconomic models against one another?

A) The rational-expectations assumption is difficult to test.
B) Macroeconomic models differ in ways that are hard to standardize for.
C) Macroeconomic models cannot be expressed in mathematical terms.
D) The amount of data available is fairly small.