This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Anti Microbial, Subject name: Pharmacology
[{'content': 'Discolouration of the teeth seen in following intake \nSelect and explain. \nA. Tetracyclines, B. Chloramphenicol, C. Minocycline, D. Lymecycline', 'role': 'user'}, {'content': 'Answer: A \nExplanation: [A) (Tetracycline) (672 - KDT 5th) (714-KDT 6th)* Tetracyclines have chelating property. Calcium- tetracycline chelate gets deposited in developing teeth and bone Given from mid pregnancy to 5 months to extra uterine life the decidous teeth are affected brown discolouration of teeth, more susceptible to carries. Tetracyclines gives between 3 months to 6 years of age affect permanent anterior dentition. Repeated course are more damaging* Prevention of discolouration of permanent front teeth requires that tetracyclines be avoided from the last 2months of pregnancy to 4 years and of other teeth to 8 years of age (or 12 years if the third molar are valued)* Prolonged tetracyclines therapy can also stain the finger nails at all ages.', 'role': 'assistant'}]