Which of the Following Statements Is True

Multiple Choice

Which of the following statements is true?

A) It is appropriate to compute a correlation coefficient for the relationship between a dummy variable and a dependent variable.
B) If a qualitative variable has m categories, you should use m - 1 dummy variables to incorporate the qualitative variable into a regression model.
C) Dummy variables are used to incorporate qualitative variables into a regression model.
D) All of these.
E) None of these.