- A Dopamine deficiency in midbrain dopaminergic neurons
- B Autoimmune destruction of myelin sheath in CNS
- C Progressive degeneration and loss of spinal motor neurons
- D Overproduction of acetylcholine at the neuromuscular junction
Correct answer: B. Autoimmune destruction of myelin sheath in CNS
Explanation: Multiple sclerosis (MS): autoimmune demyelination of CNS axons. Disrupts nerve signal conduction. Causes varied neurological symptoms, fatigue, vision problems.
Concept context
Brain, spinal cord, neurons, reflex arcs, and sense organs.