Roller Coaster's Has a WACC of 11

Roller Coaster's has a WACC of 11.6 percent, ignoring taxes.It has a target capital structure of 60 percent equity and 40 percent debt and a cost of equity of 14.27 percent.What is the cost of debt?

A) 5.5 percent
B) 7.6 percent
C) 9.3 percent
D) 9.4 percent
E) 18.7 percent