For a person consuming a vegetarian diet, which food is an adequate source of protein?

Peanut butter is considered an adequate source of protein for someone following a vegetarian diet because it contains a significant amount of protein while also providing healthy fats and calories. Specifically, it contains about 7-8 grams of protein per two-tablespoon serving. Additionally, it provides essential nutrients such as vitamin E, magnesium, and potassium.

In contrast, white rice, potatoes, and apples are not as rich in protein. White rice is primarily a carbohydrate source and has very little protein content. Potatoes do contain some protein, but the amount is relatively small compared to that found in peanut butter. Apples, while nutritious and high in fiber, do not provide a substantial protein source at all. Therefore, peanut butter stands out as a protein-rich option suitable for a vegetarian diet.