What is the coupon rate of a nine$-$year, $$10,000$ bond with semiannual coupons and a price of $$7,863\mathrm{.}50,$ if it has a yield to maturity of $7\mathrm{.}8\%?$

A$.6\mathrm{.}233\%$

B$.5\mathrm{.}342\%$

C$.3\mathrm{.}562\%$

D$.4\mathrm{.}452\%$