The energy released by 1 gram of glucose is

The correct answer is A. 6 kcal.

Glucose is a simple sugar that is used by the body for energy. When glucose is broken down, it releases 6 kcal of energy. This energy is used by the body to power its cells and tissues.

Option B is incorrect because it is the amount of energy released by 1 gram of fat.

Option C is incorrect because it is the amount of energy released by 1 gram of protein.

Option D is incorrect because it is the amount of energy released by 1 gram of alcohol.