9) A bond with a face value of $1,000 has annual coupon payments of $100 and was issued seven years ago. The bond currently sells for $1,085, has eight years left to maturity. This bond's ________ must be less than 10%.

A) current yield and coupon rate

B) coupon rate

C) yield to maturity and current yield

D) current yield

The answer C but I need to know how is it calculated. (using financial calculator if required)