Which item is not typically included as part of a standard burger?

The reason sour cream is the correct answer is that it is not a standard ingredient typically found in a classic burger. A standard burger is primarily composed of a bun (bread), a meat patty, and often includes cheese, along with typical toppings like lettuce, tomato, ketchup, mustard, and pickles. Sour cream, while it can be used as a condiment in some dishes or alternative recipes, does not belong to the traditional components of a burger, making it the item that stands out in this context.

In contrast, breads, patties, and cheese are fundamental elements of a burger, consistently present in various burger types. These ingredients complement each other to create the foundational structure and flavor profiles that most people expect when ordering a burger at a fast-food restaurant.