Question

What did Jefferson do to stop the Barbary States from pirating American ships?

Answer 1

"He blockaded the port at Tripoli" would be the best option in terms of what Jefferson did to stop the Barbary States from pirating American ships, although this was not completely effective. 

Answer 2

Jefferson blockaded the port at Tripoli in order to stop the Barbary States from pirating American ships. Option B is correct.

The First Barbary War which spanned from 1801 to 1805, also known as the Tripolitanian War and the Barbary Coast War, was the first of two Barbary Wars, in which the United States and Sweden fought against the four North African states known collectively as the "Barbary States".