GBS is often preceded by which event?

• A. Regular exercise
• B. Vitamin C deficiency
• C. Dehydration
• D. Vaccinations

Answer: (D)

Guillain-Barré syndrome is an autoimmune attack on the peripheral nerves that is often triggered by an event that stimulates the immune system. The immune response, after some triggers, can mistakenly target nerve components, leading to demyelination and weakness. While infections are the most common antecedent, vaccinations have been reported as events that can precede GBS because they activate the immune system and can, in rare cases, provoke this cross-reactive immune response. Among the given options, vaccinations fit this triggering idea, making them the best match. The other options—regular exercise, vitamin C deficiency, dehydration—do not typically initiate the autoimmune process that leads to GBS.