According to$$ Moody's, "Obligations rated Aaa are judged to be of the highest$$ quality, subject to the lowest level of credit$$ risk." What$$ "obligations" is$$ Moody's referring$$ to$?$

By$$ "obligations," Moody's means$\_\_\_\_\_\_\_\_.$

A$.$

the obligation the buyer of the bond has to hold the bond until maturity

B$.$

the obligation the bond issuer has to pay the bond holder

C$.$

the obligation of the bond issuer to provide a$$ risk$-$free investment

D$.$

the interest rate the bond issuer is obligated to pay the bond holder