Tom Ace, an equity analyst, uses the capital asset pricing model (CAPM) to help identify mispriced securities.  A consultant advises Tom Ace to use arbitrage pricing theory (APT) instead.  In comparing CAPM and APT, the consultant makes the following arguments: I. APT places more emphasis on market risk. II. Neither the CAPM nor the APT assumes investors are mean-variance optimizers. III. APT specifies the number and identifies specific factors that determine expected returns. IV. APT does not require restrictive assumptions concerning the market portfolio. Criticize the four arguments made by the consultant.