A patient is admitted to the hospital to rule out the possibility of bacterial meningitis, Which test will be most helpful in diagnosing this condition?

A. A lumbar puncture is the most important diagnostic test for suspected bacterial meningitis. It allows for analysis and culture of cerebrospinal fluid (CSF) to identify the presence of bacteria, white blood cells, protein, and glucose levels. B. Cerebral angiography is used to visualize blood vessels in the brain, not to diagnose infections like meningitis. C. Myelography evaluates the spinal cord, nerve roots, and spinal canal using contrast dye but is not used for diagnosing meningitis. D. Magnetoencephalography (MEG) is used to map brain activity, often for epilepsy or brain tumors, and is not relevant for diagnosing meningitis.