What is the survival rate at the end of three years, if the annual default probabilities are 8%, 12% and 15% in the first, second and third years,respectively?
　　A. 68.8%
　　B. 39.1
　　C. 99.9%
　　D. 65.0%
　　Answer:A
　　Survival rate = (1 - 8%)(1 - 12%)(1 - 15%) = 68.8%