O'Brien Ltd$.\text{'}$s outstanding bonds have a $$1,000$ par value, and they mature in $19$ years. Their yield to maturity is $7\mathrm{.}00\%,$

they pay interest semiannually, and they sell at a price of $$850.$ What is the bond's nominal $($annual$)$ coupon interest rate?

a$.7\mathrm{.}00\%$

b$.5\mathrm{.}56\%$

c$.2\mathrm{.}78\%$

d$.5\mathrm{.}20\%$