Final answer:
The closest estimate of the five-year CDS spread is 1.5%.
Step-by-step explanation:
In order to estimate the five-year CDS spread, we need the difference between the yield on the company's bonds and the five-year swap rate. The yield on the company's five-year bonds is 4%, and the five-year swap rate is 2.5%. Therefore, the estimated five-year CDS spread is 4% - 2.5% = 1.5%.