Sadik Inc.'s bonds currently sell for $1,200 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. 6.31%

b. 7.31%

c. 4.31%

d. 5.31%

e. 8.31%