Concept: Glucose is a carbohydrate, and carbohydrates release about 4 kcal of energy per gram.Explanation:Energy values of food nutrients are usually measured in kilocalories per gram.Carbohydrates, including glucose, provide approximately 4 kcal per gram.Proteins also provide about 4 kcal per gram.Fats provide about 9 kcal per gram, which is more than twice the energy from glucose.Therefore, 1 gram of glucose releases 4 kcal of energy.Answer: B. 4 kcal