Which of these are necessary nutrients in food?

While fruits are indeed important components of a healthy diet, they fall under the broader category of food groups rather than being classified strictly as necessary nutrients. The correct perspective recognizes that proteins, vitamins, minerals, carbohydrates, and fats are classified as essential nutrients that the body needs for proper functioning.

When considering the options provided, protein specifically is categorized as an essential nutrient because it plays a critical role in building and repairing tissues, producing enzymes and hormones, and supporting overall bodily functions. Unlike fruits, grains, and vegetables, which are all important for a balanced diet, protein is foundational to the body's structure and function.

In summary, when identifying necessary nutrients, it is accurate to emphasize protein due to its vital contributions to health, while recognizing that fruits, grains, and vegetables provide essential vitamins, minerals, and dietary fiber that contribute to overall nutrition.