What famous explorer is thought to have traveled along the silk road on his way to china?.

In exchange, horses, glassware, textiles, and manufactured goods traveled eastward. One of the most famous travelers of the Silk Road was Marco Polo

Explanation:

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I do not have your choices of "the following"  Here are some reasons I learned: Christianity, empire was too big and became hard to manage, there were many nonromans attacking parts of empire- Goths, the emperors themselves were weak or insane intrigue was rampant.