The fuel used by neurons during starvation is -

Ans. is 'd' i.e., Ketone* There is no stored fuel in brain, but it utilizes 60% of total energy under resting conditions.* Glucose is virtually the sole fuel for the brain, except in prolonged starving when ketone bodies are the major source.* Fatty acids do not serve as fuel for the brain, because they are bound to albumin in plasma; hence cannot cross blood-brain barrier.