Which of the Following Best Describes the Course of Mongol

Which of the following best describes the course of Mongol rule after Chingis Khan's death?

A) The Mongol empire rapidly disintegrated as Chingis's sons vied for power.
B) The Mongol empire continued to expand under the rule of Chingis's descendants.
C) Conquered populations began to revolt against Mongol rule and reasserted their authority in several Mongol-controlled regions.
D) The Mongol empire continued to thrive and eventually expanded into western Europe.