23 Liz Biz, a wealthy retired actress, is looking at investing in the ordinary shares of several companies. Her sharebroker has provided details of the expected returns of each company, and graphed them along with Liz’s risk–return line. The risk–

return line indicates Liz’s required return for each level of risk.

Assuming that Liz wishes to purchase all desirable shares, which ones should she buy? Explain why