Which of the following statements is true about diversification? O a. There is no benefit from diversification if the correlation coefficient is 1 Ob. The variance is the weighted average of the individual securities' variances O C By diversifying, portfolio risk can be reduced to zero Od. The benefit from divelification is maximized if the correlation coefficients is zero O e If the covariance between two securities is negative, then the portfolio's standard deviation can be reduced to zero