Unlike the Situation in China,the Struggle Between Central Authority and Local

Unlike the situation in China,the struggle between central authority and local aristocracies endured into early modern times in Japan because

A) after 450 C.E. the Japanese were opposed to the adoption of any idea or system from China.
B) China established a merit-based civil service examination system, while the Japanese maintained it as an elitist process, thus enhancing the power of the aristocracy.
C) the difficulty of overcoming the closely held power of the local rulers was so overwhelming that shoguns refused to create a strong central government.
D) the emperor always sided with the local aristocracies against the shogun.
E) both depended upon the power of the peasants.