The following stocks are available for consideration Stocks R, 25% N 12% 0 25 8 P 10 5 Q 15 12 Pro = 0.8, Psp = -0.8, PO = 0, Pop = -1, Pop = 0.8, Pro = 1, Calculate the return and risk of portfolio that is made up of the following combinations: (a) 50% in N and 50% in O (b) 30% in N, 30% in 0 and 40% in P (C) 25% in N, 25% in 0,30% in P and 20% in Q (d) Which combination is the best investment in terms of returns per unit risk