I think Vassal
Definition of Vassal <span>- </span><span>A person who received a grant of land from a lord in exchange for a pledge of loyalty and services</span>
Answer:
fleas
Explanation:
Like the modern bubonic plague, scientists believe the Plague of Justinian spread through fleas. Studies indicate the plague may have originated in China or India and was then transported to the fertile valleys of Egypt through trade routes.
John Maynard Keynes (A), Adam Smith (C), and Karl Marx (D) are all famous historical figures. However, Sigmund Freud was not an economist but instead was a famous psychologist.
