Janice Kerrman is considering two $10-$year AAA corporate bonds:

Sentinel bond is a noncallable $4\%$ coupon bond priced at $$1000.$

Colina bond is a $4\mathrm{.}5\%$ coupon bond priced at $$1000$ callable at a price of $$1020.$ Both bonds pay coupons semiannually.

Which bond should Kerrman prefer if rates are expected to rise? How will the results differ if rates fall?