Financial Managers Must Be Cognizant of Market Efficiency Because

Financial managers must be cognizant of market efficiency because:

A) manipulating earnings by accounting changes does not fool the market.
B) timing security sales is futile because without private information the current price reflects all known information.
C) there is limited price pressure from any large sale of equity depressing prices momentarily which then recover to prior levels.
D) All of the above.
E) None of the above.