The correct option is (c).
Explanation
Nutrients are classified into specific categories based on their primary physiological functions: energy-giving foods, body-building foods, and protective foods. This classification helps in understanding the specific role each nutrient plays in human physiology.
Statement-wise Analysis:
- Statement 1 is Incorrect: Proteins are primarily classified as 'body-building foods'. Their main function is the growth and repair of body tissues. While proteins can provide energy under specific conditions (such as starvation), carbohydrates and fats are the primary 'energy-giving foods'.
- Statement 2 is Correct: Carbohydrates are the main source of energy for the human body. Along with fats, they are categorized as 'energy-giving foods'.
- Statement 3 is Correct: Vitamins are micronutrients required in small quantities to ensure proper metabolic functioning. They are known as 'protective foods' because they build immunity and help protect the body against various diseases.
Key Takeaway:
The functional classification of food components is: Carbohydrates and Fats (Energy-giving), Proteins (Body-building/Growth and Repair), and Vitamins and Minerals (Protective/Immunity).