B is the correct answer.
While the Indus Valley has gotten more attention in recent years, it is not considered one of the three classical civilizations.
<span>The one topical reason for the plague portrayed by ibn khaldun which visited eurasia between the time period of 1331 and 1347 is that the rats, bugs, microbes, military clash in Caffa, as well as financial exchange or economic trade interfaces between Afro-Eurasia.
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The monarchs had used their wealth to fund expeditions for explorers. The explorers would’ve worked for them in exchange for expedition fund or to at least acquire a better chance at being funded.
