here is the question for investment, please show the calculations

4. There are three securities. 8% 2 3 9% 1 (a) Is there any security surely NOT chosen by a risk-averse investor? Why? Suppose the government bans the trading of security C, so the market has only two securities A and B. There are two risk-averse investors, Miss Red and Miss Gray. Miss Red is more risk-averse than Miss Gray. Denote Miss Red's optimal portfolio choice by PR = o A + (1 L'R) o B, and Miss Gray's optimal portfolio choice by - wc) 0B. (b) Without risk-free assets, which one is greater, or Why? [Hint: You don't need to calculate or to answer this question.] 2 (c) Suppose there is a risk-free asset with the rate of return r f Both Miss Red and Miss Gray can use the risk-free asset and a risky portfolio to form a new optimal portfolio. The optimal risky portfolios for Miss Red and Miss Gray are denoted by PR and PG, respectively. Then, which one is greater, or L'G? Why? Hint: You don't need to calculate or to answer this question.]