Question

In this question "Bob Joe’s Ice Cream is the premier ice cream shop in Southgate, Michigan. Every summer it attracts thousands of customers. To increase profit, the owner of Bob Joe’s has decided to make a delivery service. He wants to find the best method to have ice cream delivered. Mr. Joe has put an ad in the local paper for delivery man. This far a skateboarder, walker, biker, and a person with roller-blades have applied for the job. Please help Mr. Joe select the candidate that will help him deliver his delicious ice cream before it melts.
" what would the independent variable be?