An investor purchases a $30-$year, zero$-$coupon bond with a face value of $$1,000$ and a yield to maturity of $6\mathrm{.}6\%.$ He sells this bond ten years later. What is the rate of return on his investment, assuming yield to maturity does not change?

A$.3\mathrm{.}96\%$

B$.3\mathrm{.}3\%$

C$.5\mathrm{.}28\%$

D$.6\mathrm{.}6\%$