A firm has 65% probability of being worth $100 million and a 35% probability of being worth $130 million. There is one bond outstanding that promises to pay $100 million at an interest rate of 7%. The cost of capital for the firms projects is 9%. What is the promised return on the bond?

a)7.0%

b) Not determinable

c) 10.8%

d) 6.4%