The following are multiple choice questions (with answers) about medical knowledge.   **Question:** A 3-year-old boy is brought to the clinic by his parents because he ‘hasn’t been himself lately’ and reportedly gets tired very easily from his swimming classes in comparison to the other kids. He also ‘can’t catch his breath’ at times. The mother also reports that he seems to be slightly shorter than other children his age. His temperature is 36.6°C (97.9°F), blood pressure is 110/70 mm Hg, and respiratory rate is 14/min. On auscultation, a localized harsh pansystolic murmur is heard over the left sternal border at the level of the 2nd–3rd intercostal space. The murmur becomes louder when the patient is asked to squat. An echocardiogram is performed. Which of the structures below gives rise to the defective structure that is causing this patient’s symptoms?   (A) Endocardial cushion   (B) Infundibular septum   (C) 3rd pharyngeal arch   (D) Rathke’s pouch
['(A) Endocardial cushion <> answer', 'The following are multiple choice questions (with answers) about medical knowledge. <> instruction', '(A) Endocardial cushion \n (B) Infundibular septum \n (C) 3rd pharyngeal arch \n (D) Rathke’s pouch <> possible answers', '  A 3-year-old boy is brought to the clinic by his parents because he ‘hasn’t been himself lately’ and reportedly gets tired very easily from his swimming classes in comparison to the other kids. He also ‘can’t catch his breath’ at times. The mother also reports that he seems to be slightly shorter than other children his age. His temperature is 36.6°C (97.9°F), blood pressure is 110/70 mm Hg, and respiratory rate is 14/min. On auscultation, a localized harsh pansystolic murmur is heard over the left sternal border at the level of the 2nd–3rd intercostal space. The murmur becomes louder when the patient is asked to squat. An echocardiogram is performed. Which of the structures below gives rise to the defective structure that is causing this patient’s symptoms? <> context@']