(2 marks) If the single-index model is estimated to analyse the risk of two shares A and B, which of the following statement is correct? [Assume that the beta is positive for both A and B.]

		If the beta of A is over-estimated, the estimated systematic risk of A is always over-estimated if the market-index risk is correctly estimated.
		Suppose that the market index risk and the firm specific factors are not correlated, and the firm specific factors of A and B are uncorrelated. If the beta of A and B are both under-estimated, the covariance of the pair A and B is always under-estimated if the market-index risk is over-estimated.
		Suppose that the market index risk and the firm specific factors are not correlated, and the firm specific factors of A and B are uncorrelated. If the beta of A and B are both over-estimated, the covariance of the pair A and B is always over-estimated if the market-index risk is under-estimated.
		If the beta of A and B are both correctly estimated, the covariance of the pair A and B is always over-estimated if market-index risk is under-estimated.
		If the beta of A is correctly estimated, the estimated total risk of A is always over-estimated if the covariance of the pair A and B is over-estimated.