Select all that apply. A multiple linear regression model is being fit to data from a European study relating Y to age (X1), adjusting for nationality (France, England, Italy, Greece). Which of following model specifications is/are NOT appropriate? Y = 0 + 1X1 + 2X2 + 3X3 + 4X4 + 5X5 + E where X2 = 1 for France and 0 for other nationalities where X3 = 1 for England and 0 for other nationalities where X4 = 1 for Italy and 0 for other nationalities where X5 = 1 for Greece and 0 for other nationalities Y = 0 + 1X1 + 2X2 + 3X3 + 4X4 + E where X2 = 1 for France and 0 for other nationalities where X3 = 1 for England and 0 for other nationalities where X4 = 1 for Italy and 0 for other nationalities Y = 0 + 1X1 + 2X2 + 3X3 + 4X4 + E where X2 = 1 for England and 0 for other nationalities where X3 = 1 for Italy and 0 for other nationalities where X4 = 1 for Greece and 0 for other nationalities Y = 0 + 1X1 + 2X2 + E where X2