This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: DNB 2018, Subject name: Pediatrics
[{'content': 'Most common cause of syncope in a child? \nSelect and explain. \nA. Breath holding spell, B. Tantrum spell, C. Hypoglycemia, D. Neurocardiogenic', 'role': 'user'}, {'content': 'Answer: D \nExplanation: Syncope is sudden transient loss of consciousness with inability to maintain postural tone - Syncope is caused by a lack of adequate cerebral blood flow - Most common cause of syncope in the normal pediatric population is neurocardiogenic syncope, which is also known as vasovagal syncope.', 'role': 'assistant'}]