4.3. [2-500:20] It has been suggested that companies often overstate earnings in bad years and understate them in good years because they want investors to believe that the cash flows are less variable than they actually are. Which of the following, if true, would cast the most doubt on the sensibility of this strategy? (A) Investors are risk-averse. (B) Earnings follow a random walk. (C) The strong efficient market hypothesis holds. (D) Investors rely on historically observed betas. (E) Corporate tax rates increase with earnings