单选题 The risk-free rate is 4% , and John's portfolio has an expected return of 15% and a standard deviation of 30%, John is concerned that the portfolio might earn less than 10%, What is the safety-first ratio for John's portfolio?
【正确答案】 C
【答案解析】The ratio=(ER-Rlower)/σ=(15%-10%)/30%=0.167.