Company A has a beta of 0.60, while Company B's beta is 1.50. The required return on the stock market is 9.00%, and the risk-free rate is 2.25%. What is the difference between A's and B's required rates of return? (Hint: First find the market risk premium, then find the required returns on the stocks.) Do not round your intermediate calculations.

a. 6.075%

b. 6.300%

c. 4.050%

d. 9.338%

e. 8.100%