Which of the following statements concerning diversification and portfolios is not true? A. Adding additional securities into a portfolio will reduce the idiosyncratic risk of the portfolio, provided they are not perfectly positively correlated with each other. B. Adding additional securities into a portfolio will reduce the systematic risk of the portfolio, provided they are not perfectly positively correlated with each other. C. When you add a new security into an already diversified portfolio, the beta of the new security is more important for assessing the change in portfolio risk than the standard deviation of the new security. D. The total risk of a portfolio is best measured by its standard deviation. Which of the following statements about beta is not true? A. The return of a security with a negative beta would tend to move in the opposite direction of the market return on a given day. B. The larger the beta of a security, the more exposed the security is to systematic risk. C. If a security has a low R-squared (R) when measuring its beta, its returns are well explained by corresponding market returns. D. If a security has a high R-squared (R) when measuring its beta, its returns are well explained by corresponding market returns