Several passengers aboard an airliner suddenly become weak and suffer breathing difficulty. The diagnosis is likely to be
Correct Answer: B
Rationale: In the scenario described, where multiple passengers on an airliner experience sudden weakness and breathing difficulty simultaneously, the most likely cause is chemical exposure. This is because a sudden onset of similar symptoms in a group of individuals suggests a common environmental factor affecting them. Options A, C, and D are less likely as they do not explain a sudden onset of symptoms in multiple individuals simultaneously. Asian flu (Option A) is a viral infection and would not typically result in sudden symptoms in multiple individuals at the same time. Bacterial pneumonia (Option C) is a localized infection and not a probable cause for a sudden onset of symptoms in a group. An allergic reaction (Option D) would usually occur in individuals with specific allergies rather than affecting a group of passengers at the same time.