"if a company assigns individual teams of salespeople to big retail customers, it is most likely to have a sales force structure."

The answer is a market sales force structure.

Explanation:

Territorial sales force structure consists of a sales force organization that has the purpose of assigning each salesperson into a specific geographic territory. In this geographic territory, the salesperson sells company's products to all the different customers.

This organization also establishes the job related to each salesperson, as well as fixes accountability. The organization allows the salesperson to have or build a relationship with the customer to improve selling effectiveness.