In the Face of Peasant Insurrections and Civil Wars in the 1350s

In the face of peasant insurrections and civil wars in the 1350s, the Mongol leaders

A) wrung as much tribute as they could from the Chinese population and neglected the country's infrastructure needs
B) mounted a full-throated military response
C) abandoned China and retreated to their steppe homeland
D) invested in the country's roads, canals, and irrigation and flood-control dikes to shore up the Chinese economy