Which Statement Does NOT Explain Why China Did Not Colonize

Which statement does NOT explain why China did not colonize an overseas empire?

A) The regions explored by China did not have the goods that China wanted.
B) Chinese primitive shipbuilding technology prevented Chinese explorers from reaching other continents.
C) China was more concerned with fortifying the Great Wall of China against Mongolian invaders.
D) Explorers did not have the support of the Chinese government and were therefore limited in their travels.