Answer:
The answer is fats (lipids).
Step-by-step explanation:
When the question says “energy”, it is referring to Calories/kcal, because Calories are simply a measurement of energy. When the question says “per unit of weight”, we weigh the calories in each of these items as grams. Therefore, fats/lipids provide the most calories per gram, and thus yield the most energy per unit of weight. Fats/lipids have 9cal/gram, which is far more than carbohydrates (4cal/gram), proteins
(4cal/gram), and sugars (4cal/gram).