The correct answer is "2".
The Mongol Empire was the largest land empire in history. It originates in present-day Mongolia. At its peak, it stretched from Eastern Europe to the Sea of Japan.
The Mongols were very supportive of trade. They engaged in the maintenance of trade routes that linked lands in the Mediterranean basin to China. This route would become to be known as "The Silk Road". This famous route would be later used by Marco Polo.