Answer:
The money
Explanation:
The drive to the farmers market is a certain distance away, which costs him a specific amount of money. If the distance were to change, then so would the price it took to get there per week. Additionally, as the amount of boxes increases, so does the price.
A dependent variable is a variable that directly changes as the independent variable(s) change. In this scenario, the money, or cost is what's changing based on other factors.
hope this helps :)