Which are the 2 correct statements ?

1- A portfolio in which each security is held in proportion to its market capitalization is called a price-weighted portfolio.

2- If investors hold the efficient portfolio, then the cost of capital for any investment project is equal to its required return calculated using its beta with the efficient portfolio.

3- All investors should demand the same efficient portfolio of securities in the same proportions.

4- The Capital Asset Pricing Model (CAPM) allows corporate executives to identify the efficient portfolio (of risky assets) by using knowledge of the expected return of each security.

5 - Beta measures the diversifiable risk of a security, as opposed to its market risk, and is the appropriate measure of the risk of a security for an investor holding the market portfolio.