Which statement best defines proteins in the context of macronutrients?

• A. Polymers of monosaccharides that are the main immediate source of blood glucose after a carbohydrate-rich meal.
• B. Organic macronutrients that are primarily used for long-term energy storage in adipose tissue and occasionally serve as structural components in cells during extended metabolic processes when metabolic hormones shift substrate partitioning toward fat deposition.
• C. Macronutrients composed of one or more chains of amino acids.
• D. Small molecules derived from fatty acids that form cell membranes and provide insulation and concentrated energy stores.

Answer: (C)