$15.$ Moon Inc.$\text{'}$s outstanding bonds have a par value of $$1000$ and maturity of $25$ years. Their yield to maturity is $9\mathrm{.}25\%,$ they pay interest semiannually, and currently sell at a price of $$975.$ Find the bond's nominal coupon interest rate.

a$.8\mathrm{.}99\%$

b$.8\mathrm{.}01\%$

c$.7\mathrm{.}99\%$

d$.9\mathrm{.}19\%$

e$.6\mathrm{.}62\%$