Which one of the following statements is most likely correct according to risk -return -reward relation and CAPM for a financial security ? a The risk premium is unrelated to the average rate of return . b The greater the total variance of returns , the greater the risk premium . c The greater the total systematic of returns , the greater the risk premium . d The lower the total volatility of returns , the greater the risk premium . e The risk premium is not affected by the variance of returns