Which of the following is a common side item on McDonald's menu?

French fries are a signature side item on McDonald's menu, widely recognized for their crispy texture and iconic taste. They have been a staple of the McDonald's brand since its inception and are often considered one of the most popular fast-food items globally. The unique preparation method, which includes the use of vegetable oil and a specific blend of seasonings, along with their golden-brown appearance, contributes to their appeal.

In contrast, while onion rings, salads, and pita chips may be offered by various fast-food establishments, they do not hold the same iconic status or universal availability across McDonald's locations. French fries, on the other hand, are fundamental to the McDonald's experience, frequently appearing in promotional materials and advertisements, making them a quintessential side item that embodies the brand.