(b) Please outline and explain the rationale, advantages and disadvantages (if any) for the portfolio selection methodology proposed by Treynor and Black, under the assumption that the model of asset returns is the Single Index Model with the market factor as the sole index. In your answer, at a minimum, you should i. 11. List and briefly describe the inputs required to implement the portfolio selection methodology proposed by Treynor and Black, under the assumption that the model of asset returns is the Single Index Model with the market factor as the sole index. Outline and offer an intuitive explanation of the rationale for the key steps that must be undertaken to form mean-variance optimal portfolios according to the methodology proposed by Treynor and Black, under the assumption that the model of asset returns is the Single Index Model with the market factor as the sole index. Explain the overall rationale of the above portfolio construction methodology, pointing out advantages and disadvantages, ideally relating it to modern approaches to portfolio choice such as so called "factor investing