PLZ I NEED HELP

How did trade contribute to the spread of the plague in the 1300s?
O Trading vessels from the Americas brought the plague to London, where it spread across Europe.
O Trading caravans from Mongolia brought the plague to Rome, where it spread across Europe.
O Trading caravans from Russia brought the plague to Barcelona, where it spread across Europe.
O Trading vessels from China brought the plague to Sicily, where it spread across Europe.