Sadik Inc.'s bonds currently sell for $1,270 and have a par value of $1,000. They pay a $105 annual coupon and have a 15-year maturity, but they can be called in 5 years at $1,100. What is their yield to call (YTC)?

a. 6.89% b. 5.89% c. 5.18% d. 6.54% e. 6.30%