Roisin consumes only two goods, X and Y, and her utility function is given by U = XY. Her income is E100 and the price of X is E20 and the price of Y is E5. In equilibrium Roisin will choose which combination of X and Y? Partial units are possible. O A. X = 5; Y =20 O B. X = 2.5, Y = 10 O C. X = 10, Y = 10 OD.X = 5, Y =5