I know that the answer to the question is C I just need to know how to work out the problem by hand. Thanks for any and all help!

20. Consider the following two stocks, A and B. Stock A has an expected return of 10% and a beta of 1.20. Stock B has an expected return of 14% and a beta of 1.80. The expected market rate of return is 9% and the risk-free rate is 5%. Security would be considered a good buy because A) A, it offers an expected excess return of 0.8%. B) A, it offers an expected excess return of 2.2%. C) B, it offers an expected excess return of 1.8%. D) B, it offers an expected return of 2.4%