Correct Option: B

The blood sugar concentration or blood glucose level is the amount of glucose (sugar) present in the blood of a human or animal. The body naturally tightly regulates blood glucose levels as a part of metabolic homeostasis. Glucose is the primary source of energy for the body’s cells, and blood lipids (in the form of fats and oils) are primarily a compact energy store. The mean normal blood glucose level in humans is about 4 mM (4 mmol/L or 72 mg/dL, i.e. milligrams/ deciliter); however, this level fluctuates throughout the day.