How did Venice and Genoa create a powerful trade monopoly? (This is from History Alive! The Medieval World and Beyond)

The correct answer to this open question is the following.

Although there are no options attached we can say the following.

Venice and Genoa created a powerful trade monopoly because of the beautiful, special, and sophisticated things that could be found in these cities. Venice and Genoa could create this monopoly on trade because they had great locations. These cities were on the coast, so they have functional ports where many ships arrived daily with all kinds of goods to be traded. This number of ships brought with them merchants that sold their exclusive goods and Venice and Genoa could hoard them to offer them to different buyers, creating a monopoly.

All the luxurious goods from Asia arrived at the main ports of Genoa and Venice and from there, they were shipped to other European nations. Money flowed daily in big amounts.

where is the map at?