Question

which nutrient serves as a major source of energy?
proteins
fats
carbohydrates
vitamins

Explanation:

Carbohydrates are the body's main source of energy. They are broken down into glucose, which is used by cells for energy. Fats are a concentrated source of energy but are not the major source. Proteins are mainly for growth, repair, and maintenance. Vitamins are essential for various metabolic processes but do not provide energy.

Answer:

carbohydrates