Identify a system of commerce used by the Aztecs.

The Aztecs employed a complex system of commerce that included the use of cacao beans and cotton as forms of currency. Cacao beans were particularly significant, as they were not only a vital ingredient in beverages enjoyed by the elite but also served as a recognized medium of exchange. Their value was further enhanced by the fact that they were used to create a popular drink, thus intertwining commerce with cultural practices.

Cotton was also an important commodity, often used in trade and as currency because of its value in society for making textiles and clothing. The dual-use of these items in both direct trade and as currency illustrates the Aztec economy's sophistication, allowing for a system of commerce that facilitated the exchange of goods and services effectively.

Unlike some alternatives, which focus on bartering or labor exchange without a structured currency system, the Aztec approach integrated certain products as standardized forms of value, enhancing trade and commerce throughout their civilization.