Final answer:
The physician removes fluid from the spinal cavity (d) during a spinal tap, which is conducted to analyze cerebrospinal fluid for the diagnosis of conditions like meningitis.
Step-by-step explanation:
During a medical test for spinal meningitis, a physician orders a spinal tap to remove cerebrospinal fluid for analysis. This procedure is performed to diagnose conditions affecting the central nervous system, such as meningitis. The fluid is extracted from the spinal cavity, which is the correct answer to the student's question and corresponds to option d) Spinal cavity.
The spinal cavity is a long, narrow cavity contained within the vertebral column and houses the spinal cord. In a spinal tap, or lumbar puncture, a needle is inserted into the lumbar region of the spinal column to withdraw the cerebrospinal fluid, which should normally be clear. This fluid surrounds both the brain and the spinal cord, providing protection and playing a vital role in maintaining the central nervous system's health. Any abnormalities in the fluid, such as bacteria indicating infection, can be identified through laboratory analysis.