Which action is linked to the spread of the Black

Death to Europe during the 14th century?

(1) trade with Asia

(2) conquest of Japan

(3) trade across the Sahara

(4) exploration of the Western Hemisphere

I'm pretty sure (1) Trade with Asia is right because the plague was carried by rats on ships coming from the East to the West.

Also, you can guess by the dates. The Black Death was in the 12th and 13th centuries, while conquest of Japan and exploration of the Western Hemisphere were in the 14th century.