Suppose Wish to Explain Violent Crime as a Function of City

Multiple Choice

Suppose wish to explain violent crime as a function of city type and unemployment rate and you are concerned that the marginal effect of the unemployment rate might differ for cities and suburbs.You could control for this possibility by

A) including the binary dummy variable Suburb in you regression.
B) interacting the binary dummy variable with the unemployment rate in you regression.
C) including the square of the unemployment rate in you regression.
D) including the binary dummy variable City in your regression.