McDonald's is trying to fight its "pink slime" reputation, one menu item at a time. The fast food restaurant's latest commercial addresses the rumor that their fries are not made from real potatoes.

There are matchstick fries and steak fries; crinkle-cut fries and waffle fries; cheese fries and sweet potato fries. But among all the rest, McDonald’s french fries are an old standby. There’s ...