Question

Which of the following contributed to the downfall of the Roman Empire but not the Han Dynasty?

A: It split into western and eastern empires
B: It grew too large to govern efficiently
C: It was attacked by foreign invaders
D: It was led by weak leaders

Answer 1

The correct answer is A. It split into western and eastern empires. 
This happened to the Roman Empire in 284 AD. 

Answer 2

The Roman Empire by 285 CE become so vast that it was difficult to rule all the provinces directly from Rome. Diocletian the Roman Emperor, therefore, divided the empire into two halves known as the Western ( governed from Rome) and the Eastern Roman Empire ( ruled by Byzantine). The western half of the Empire had a more severe fall than the Eastern portion of Rome.

This was the only difference in the decline of the Roman empire and the Han Dynasty of China. Other three options were similar in one or another way in the decline of Rome and of the Han dynasty.