Given Mr. Young's portfolio listed below, which of the following portfolios is the least risk? A portfolio of U.S. common stocks of small firms A portfolio of Treasury bills A portfolio of long-term U.S. government bonds A portfolio of U.S. common stocks of large firms Question 55 What is true regarding capital asset pricing models (CAPM)? 1 pts The expected rate of return on an investment is determined entirely by the risk-free rate and the market rate of return. The expected rate of return on an investment is proportional to its beta. The expected risk premium on an investment is proportional to its beta The expected rate of return on an investment is determined entirely by the risk-free rate