Answer: (B) Glucose
Explanation: The brain relies almost entirely on glucose for its energy needs. Glucose is the primary fuel for brain cells, and because the brain has a high demand for energy, it requires a constant supply of glucose from the bloodstream. While other nutrients like fatty acids and proteins are impor tant for the body, they are not the brain’s main source of energy. Insulin, on the other hand, is a hormone that helps regulate glucose levels in the blood, but it is not a direct energy source for the brain.
