When using historical data to estimate the market risk premium and CAPM betas, which of the following are, generally speaking, true?
A) The market risk premium is calculated as the difference between the expected return on the market and the risk-free rate.
B) CAPM betas are estimates of the sensitivity of a security's returns to changes in the overall market returns.
C) Historical data provides accurate predictions of future market conditions.
D) CAPM betas are constant over time and do not change with market conditions.
