Answer: c. higher than 6.44%.
Explanation: a bond's rating is a measure of it's credit quality, that is, how likely a bond issuer is to repay its loan (risk of default) to investors. If any of the factors that influence credit ratings such as the bond issuer's capital structure, credit payment history, revenue, and earnings, causes a bond's rating to fall, the bond yields must increase and the price of the bond lowered to reflect more risk of default. therefore, the year to maturity (YTM) should be higher than 6.44%.