What does a positive Brudzinski's sign indicate?

A positive Brudzinski's sign specifically indicates that a person experiences pain or discomfort when the neck is flexed. This clinical sign is primarily associated with meningitis, an inflammation of the protective membranes covering the brain and spinal cord. When a clinician flexes the neck of a patient with suspected meningitis, reflexive bending of the knees and hips may occur due to the increased sensitivity and irritation of the meninges. This involuntary response signifies neurological involvement and the presence of meningeal irritation, which is why option B is the correct answer.

Muscle spasms do not correlate directly with Brudzinski's sign, as the sign is more about the response of the legs to neck flexion rather than stiffness or spasms in the muscles. Numbness in the extremities and loss of motor control do not directly relate to Brudzinski's sign; these symptoms could indicate other neurological conditions but are not specific to the sign itself.