Answer:
the development of fore-and-aft rigging and rudders on ships.
Step-by-step explanation:
The han period was a period between 202 BC and 220 BC, when the han dynasty created by the rebel leader named Liu Bang was in existence. The han dynasty was ruled by the House of Liu.
The invention that led to major expansion of trade in the han period was the development of fore-and-aft rigging and rudders on ships.