Based on the capital asset pricing model, which one of the following must decrease the expected returns on an individual security, all else constant?

A. A increase in risk free rate given a security beta of 1.62

B. An increase in the market rate of return given a security beta of 1.37

C. An increase in the market rate of return given a security beta of 0.51

D. An increase in the risk free rate given a security beta 0.45