Heeeelp me please.
Which statement accurately describes an accomplishment of Emperor Yangdi that helped bring the Chinese together as one people?	
 A.
He brought a patchwork of small kingdoms under one rule by rebuilding the army.
 B.
He helped spread Buddhism throughout Mongolia and Southeast Asia.
 C.
He built a vast network of canals for trade and communication, known as the Grand Canal.
 D.
He convinced Marco Polo to share the technology of Western Europe with all regions of China.