Both assets B and C plot on the SML. Asset B has a beta of 1.3 and an expected return of 13.1%. Asset C has a beta of .50 and an expected return of 7.50%. The risk-free rate is 4% and the expected return on the market portfolio is 11%. If you wish to hold a portfolio consisting of assets B and C, and have a portfolio beta equal to 1.0, what proportion of the portfolio must be in asset B? 

A) 0.375 

B) 0.50 

C) 0.625

D) 0.75