Dollar bills in the modern economy serve as money because A. they are backed by the gold stored in Fort Knox. B. they can be redeemed for gold by the central bank. C. they have value as a commodity...

Dollar bills in the modern economy serve as money because

A. they are backed by the gold stored in Fort Knox.

B. they can be redeemed for gold by the central bank.

C. they have value as a commodity independent of their use as money.

D. people have confidence that others will accept them as money.