The Following Graph Shows the Supply of and Demand for Baseballs

The following graph shows the supply of and demand for baseballs in the United States.If the world price is $3 per baseball and a tariff of $1 per baseball is imposed,then the tariff revenue collected by the United States government is _____.

A) $4,000
B) $16,000
C) $20,000
D) $24,000
E) $48,000