<prompt> Please answer with one of the option in the bracket. Write reasoning in between . Write answer in between .Q:A 5-year-old girl swallows a marble while playing and is rushed to the hospital by her mother. The patients mother says she suddenly started to cough violently and made funny breathing sounds for a few minutes which then resolved. Her pulse is 100min and respirations are 28min. Physical examination reveals a girl in no obvious distress and breathing comfortably. There are diminished breath sounds and mild expiratory wheezing over the lower right lung field. A chest X-ray is performed which shows a round foreign body about 1 cm ×1 cm in the lower portion of the right inferior lobe. Which of the following changes in blood flow through the affected part of the lung would most likely be present in this patient?? A: Blood flow would be increased due to arterial vasodilation., B: Blood flow would be increased due to active hyperemia., C: Blood flow would be unchanged due to autoregulation., D: Blood flow would be unchanged due to decreased surfactant., E: Blood flow would be decreased due to arterial vasoconstriction.,  <response>: This is a medical question involving a child who swallowed a marble and now has respiratory symptoms and lung exam findings concerning for a foreign body aspiration. The key details in the stem are the acute onset of coughingchoking symptoms after swallowing a marble, diminished breath sounds and wheezing on exam localized to the right lung, and a chest X-ray showing a foreign body in the right lower lobe. The question asks about expected changes in blood flow to the affected part of the lung. Foreign body aspiration causes localized inflammation and irritation, which triggers vasoconstriction of local pulmonary arteries to that region as a protective mechanism. This decreases blood flow to the irritatedinflamed region. Choices A and B can be eliminated because vasodilation and active hyperemia would increase, not decrease, blood flow. Choice C can be eliminated because autoregulation maintains constant blood flow despite changes in perfusion pressure, but does not compensate for mechanically-induced changes in vessel diameter. Choice D is irrelevant since surfactant has no direct role in regulating pulmonary blood flow. E: Blood flow would be decreased due to arterial vasoconstriction. 