Which order of contacts most likely traces the spread of the bubonic plague to medieval Europe?
rats in Chinese cities, conquering Mongol armies in Asia, fleas with travelers to the Middle East and Europe
conquering Mongol armies in Asia, rats in Chinese cities, fleas with travelers to the Middle East and Europe
fleas with travelers to the Middle East and Europe, conquering Mongol armies in Asia, rats in Chinese cities
conquering Mongol armies in Asia, fleas with travelers to the Middle East and Europe, rats in Chinese cities