The correct answer is B. Diseconomies of scope
Step-by-step explanation:
In businesses, diseconomies of scope occur when costs increase when two or more products are produced by the same business. This means it is cheaper and more efficient for a business to specialize in a few products rather than focusing on diverse products. This occurs in the case presented because the production of turkey dogs and ham sandwiches increased the costs, which shows it is more efficient for the business to specialize in a few products. Thus, this vendor is experiencing diseconomies of scope.