Final answer:
An example of a single-intermediary channel of distribution is when a retailer sells directly to a customer.
Step-by-step explanation:
An example of a single-intermediary channel of distribution is 4) Retailer sells to a customer. In this scenario, the retailer acts as the intermediary between the manufacturer and the customer. The retailer purchases the products from the manufacturer and then directly sells them to the customer. There are no additional intermediaries involved in the distribution process.