Which of the following is NOT one of the three types of carbohydrates?

The identification of protein as the option that is not one of the three types of carbohydrates highlights an important distinction in nutrition. Carbohydrates are classified into three main types: sugars, complex carbohydrates (often found in starches), and fiber. Each of these plays a different role in the body—sugars provide quick energy, complex carbohydrates offer sustained energy release, and fiber contributes to digestive health.

On the other hand, protein is a separate macronutrient essential for the repair and growth of tissues, functioning differently from carbohydrates. By clarifying this separation, it becomes clear why protein does not belong to the carbohydrate category, reinforcing the understanding of macronutrient functions in overall nutrition.