Final answer:
Lipids provide the most energy per gram, yielding about 9 calories per gram, whereas carbohydrates and proteins both provide about 4 calories per gram. Vitamins do not yield energy.
Step-by-step explanation:
The nutrient that yields the most energy per gram is lipids (b). While carbohydrates, proteins, and fats are all macronutrients that provide energy, they do so at different rates. Lipids offer approximately 9 calories per gram, which is more than double the energy provided by either carbohydrates or proteins, which both yield about 4 calories per gram. Vitamins do not provide energy; instead, they are essential for various metabolic processes in the body. Macronutrients like lipids are crucial for building cell membranes and serving as a major energy store for the body. Fats, also known as lipids, have a higher energy density compared to carbohydrates and proteins. One gram of fat provides about 9 calories, while one gram of carbohydrates or protein provides about 4 calories each. Therefore, lipids are the macronutrient that provides the most energy per gram.