Final answer:
Barbie, as a vegan, would eat Tofu Stir-Fry because it does not contain any animal products. Other options like chicken nuggets, cheeseburgers, and pepperoni pizza contain animal products and are not vegan.
Step-by-step explanation:
Barbie, being a vegan, chooses to eat foods that do not contain animal products or by-products. Among the options provided, b) Tofu Stir-Fry is the food she would eat. Tofu is a soy-based product that is a popular meat substitute in vegan diets. Chicken nuggets, cheeseburgers, and pepperoni pizza all contain animal products, therefore, they are not suitable for a vegan diet.