Given a portfolio of 30 shares, how many variance and unique covariance terms can be estimated using the Markowitz mean-variance portfolio approach? a. 30 variances; 30 covariances. b. 30 variances: 870 covariances. O C. 30 variances; 15 covariances. d. 30 variances; 435 covariances. e. 30 variances; 60 covariances. QUESTION 20 Suppose the annual risk-free rate is 196. The expected annual return on IBM stock and its standard deviation is 5% and 0.25%, respectively. If a portfolio consisting of the risk-free asset and IBM stock yields a 29 annual return, what is the risk of the portfolio as measured by standard deviation? O a. 0.034596. O b. 0.042596. O c. 0.051596. O d. 0.062596. e. None of the above