Question

what do the products traded by the Arabs suggest about commerce in the Indian Ocean in the twelfth and thirteenth centuries?

Answer 1

The products that traded in Indian Ocean in the twelfth and thirteenth centuries  were spices, gold, precious stones, leather of rare animals, ebony and pearls. 
Back then, these commodities were considered really luxurius, so it suggest that all the nations that involved in the trades will most likely to have a strong economy and very culturized.