Walmart is financed entirely by common stock that is priced to offer a 15 percent expected return. If the company repurchases 25 percent of the common stock and substitutes an equal value of debt yielding 6 percent, what is the expected return on the common stock after refinancing? (Ignore taxes.)

A. 18 percent

B. 21 percent

C. 15 percent

D. 10.5 percent