In the United States,bimetallism Was Adopted by the Coinage Act

In the United States,bimetallism was adopted by the Coinage Act of 1792 and remained a legal standard until 1873,

A) when Congress dropped the silver dollar from the list of coins to be minted.
B) when Congress dropped the twenty-dollar gold piece from the list of coins to be minted.
C) when gold from the California gold rush drove silver out of circulation.
D) when gold from the California gold rush drove gold out of circulation.