题目选项分析

Between 1979 and 1981 the United States minted about 857 million silver-colored "Susan B . Anthony" dollars, which proved unpopular because it looked and felt too much like a quarter.

The United States minted about 857 million silver-colored "Susan B . Anthony" dollars between 1979 and 1981, but the coin proved unpopular because it looked and felt too much like a quarter.