Which statement below best describes what happens during a stroke, its common causes, the typical immediate effects on the brain and body, and the role of the FAST tool?

• A. A temporary decline in brain blood flow (often from dehydration) causing tiredness and memory lapses; FAST screens for mild, non-urgent cognitive issues.
• B. Stroke always results from a clot from the legs that briefly causes sensory changes with no lasting effects; FAST guides over-the-counter pain relief.
• C. Infection of brain tissue causing fever and generalized weakness; FAST tracks symptoms over several days.
• D. Sudden loss of blood flow to part of the brain from a blocked or ruptured artery, causing oxygen deprivation and one-sided weakness or speech problems; FAST prompts rapid emergency care.

Answer: (D)