An investor considers the purchase of an AA rated $7-$year, $4\mathrm{.}5\%$ coupon bond that is callable in $3$ years at $103.$ If the bond is trading at $$950,$ which of the risks should the investor be least concerned about over the next two years?

Group of answer choices

Prepayment risk.

Loss of principal.

Default risk.

Reinvestment rate risk.