This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Pathology
[{'content': 'Feature of deficiency of the enzyme alkaline phosphatase: \nSelect and explain. \nA. Absence of cementum., B. Resorption of bone., C. Ankylosis of teeth., D. All of the above.', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Hypophosphatasia is due to deficiency of enzyme alkaline\xa0phosphatase in serum or tissues and excretion of phosphoethanol amine in the urine.\nLoosening and premature loss deciduous teeth. Chiefly\xa0the incisors, irregular qualifications of metaphyses of long\xa0bones are important features. The teeth characteristically\xa0shows absence of cementum as a result of failure of\xa0cementogenesis. So, there is no sound functional attachment\xa0of the tooth to bone by periodontal ligament and this\xa0accounts for early toss of deciduous teeth.', 'role': 'assistant'}]