This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Environment & Nutritional Pathology, Subject name: Pathology
[{'content': 'Petechial hemorrhages were noticed on the upper and lower extremities of a 5-day-old infant. Hemorrhagic disease of the neonate was most likely caused by a deficiency of which of the following vitamins? \nSelect and explain. \nA. Vitamin B2 (riboflavin), B. Vitamin D, C. Folic acid, D. Vitamin K', 'role': 'user'}, {'content': 'Answer: D \nExplanation: Hemorrhagic disease of the new-born may be caused by a deficiency of vitamin K. Vitamin K is an important coagulation factor, which is necessary for the carboxylation and activation of prothrombin, as well as of clotting factors VII, IX, and X. Newborn infants frequently exhibit vitamin K deficiency because the vitamin is not transported well across the placenta, and the sterile gut of the new-born does not have bacteria to produce it. The other vitamin deficiencies do not impair coagulation.Diagnosis: Vitamin K deficiency, hemolytic disease of the newborn', 'role': 'assistant'}]