I have these risky assets. Which one is the best that you choose? (risk free rate is 4%) Hint: It means which one has the best trade-off between risk and return. Use the measure (ratio) that we use to calculate how much return can you generate for each unit of risk. Portfolio A: E[r] = 10%, Std. Dev.= 6% Portfolio B: E[r] - 16%, Std. Dev.= 7% Portfolio C: E[r) - 18%, Std. Dev.- 21% Portfolio D: E[r] - 19%, Std. Dev.= 7% B Portfolio A: E[r] - 10%, Std. Dev.= 6% Portfolio B: E[r) = 16%, Std. Dev.= 7% Portfolio C: E[r] 18%, std. Dev. = 21% Portfolio D: E[r] = 19%, Std. Dev.= 7% B D