Consider a $1000, 4-year, 10% coupon bond that can be purchased for a bargain- basement $850. It is known that the bond is risky and you - as investment advisor - are asked by your client what fixed probability of default would just give them a zero yield on that bond. Your (approximate) answer would be a probability of default between 10%-20% 30%-40% 40%-50% 20%-30%