From Time to Time, the U

From time to time, the U.S. Treasury has introduced dollar coins. The hurdles faced in doing this include all of these EXCEPT:

A) some industries would incur added costs because of dealing with the coins.
B) dollar coins may cause confusion with similar-sized coins.
C) the dollar bill continues to be used.
D) over time, the total cost of using coins is greater than the total cost of using bills.