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: Dental
[{'content': 'An 18 years old male reported with chief complaint of sensitivity and deep, dull, radiating pain during chewing. Intra-oral examination showed sparase plague and dental calculus deposits, distolabial migration of the maxillary incisors with diastema formation, mobility of maxillary and mandibular incisors and first molars. Prescribed radiographs showed an arch shaped loss of alveolar bone extending from the distal surface of the mandibular second premolar to the mesial surface of the second molar. There was vertical bone loss in the maxillary incisor region.\n\nThe host modulation therapy that may be used as adjunctive therapy for this disease is \nSelect and explain. \nA. Subantimicrobial-dose clindamycin, B. Subantimicrobial-dose metronidazole, C. Subantimicrobial-dose doxycycline, D. Subantimicrobial-dose ciproftoxacin', 'role': 'user'}, {'content': 'Answer: C \nExplanation: None', 'role': 'assistant'}]