In an efficient market, the market price is defined to be an unbiased estimate of the true value. This implies that
(a) the market price is always equal to true value.
(b) the market price has nothing to do with true value
(c) markets make mistakes about true value, and investors can exploit these mistakes to make money
(d) market prices contain errors, but the errors are random and therefore cannot be exploited by investors.
(e) no one can beat the market.