单选题 Which one of the following statements best describes the components of the required interest rate on a security? A. The real risk - free rate, the expected inflation rate, the default risk premium, a liquidity premium and a premium to reflect the risk associated with the maturity of the security. B. The real risk -free rate, the default risk premium, a liquidity premium and a premium to reflect the risk associated with the maturity of the security. C. The real risk - free rate, the expected inflation rate and a liquidity premium.