As your company's risk manager, you are looking for protection against adverse interest rate changes in five years. Using Black's model for options on futures to price a European swap option (swaption) which gives the option holder the right to cancel a seven-year swap after five years, which of the following would you use in the model?
A. The two-year forward par swap rate starting in five years time
B. The five-year forward par swap rate starting in two years time
C. The two-year par swap rate
D. The five-year par swap rate