State whether the following statements are true or false.

A. Investors demand higher expected rates of return on stocks with more variable rates of return.

B. The capital asset pricing model predicts that a security with a beta of zero will provide an expected return of zero.

C. An investor who puts $10,000 in Treasury bills and $20,000 in the market portfolio will have a portfolio beta of 2.0.

D. Investors demand higher expected rates of return from stocks with returns that are highly exposed to macroeconomic changes.