Suppose that a researcher estimated the following regression model: (3) WAGEi = 2.05 - 0.58GENi 1.31EDUi 0.32EDUi GENi ei where WAGEi is the individual i's wage ($/hour), EDUi is i's education (measured in years), and GENi is a dummy variable representing i's gender (GENi = 1 if i is male and 0 if female). In this model, which of the following is appropriate as an interpretation of the coefficient for EDU? a. It represents the expected change in hourly wage of a male worker when he achieves another year of education. b. It represents the expected change in hourly wage of a female worker when she achieves another year of education. c. It represents the average change in hourly wage when a worker (either male or female) achieves another year of education. d. It represents the difference between male and female in the marginal effect of education on hourly wage