Answer:
B). Trade increased as the Silk Roads were unified under one empire.
Step-by-step explanation:
As per the given description in the passage, 'the trade witnessed a huge expansion during the Yuan dynasty due to the integration of Silk roads under one empire'. The 'Silk Roads' became a convenient mode(trade route) of transportation that assisted the trade to augment more impactfully during the Yuan dynasty. It made the trade more integrated and beneficial. Hence, the dynasty was able to rule the Chinese territory for 'more than hundred years'. Thus, option B is the correct answer.