please solve everything because every options are1 question already.

Portfolio Optimization You are considering investing in four stocks, and have collected the following information on them: Stock Price per Share Dividend per Share Risk Coefficient A $10 $0.05 2.5 B $20 $0.10 2.0 C $30 $0.08 1.5 D $40 $0.04 1.0 a) You have $120,000 to invest. How much should you invest in each stock in order to maximize the total dividents you will receive if - you don't want to invest more than one-half the money in stock D - you want to have at least 500 shares of each of each stock - the total weighted risk of investment must be no more than 1.75? b) How much should you invest if the risk coefficient of Stock B will increase to 3.0? c) How much should you invest if the divident per share of Stock B will decrease to $0.09