This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: General pharmacology, Subject name: Pharmacology
[{'content': 'Beta-Lactamases cause resistance to penicillins and cephalosporins by \nSelect and explain. \nA. Breaking one chemical bond, B. Breaking two chemical bonds, C. Adding amino (NH2) groups to a molecule, D. Inhibiting transpeptidase enzymes', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Penicillins and cephalosporins are called beta-Iactam drugs because of the impoance of the intact BETA-lactam ring for antimicrobial activity. -Lactamases inactivate these drugs by breaking the single bond in their BETA-lactam ring. BETA-Lactamases are coded for by either a transferable plasmid or by the genome of the organism. Plasmids are extrachromosomal genetic elements that may be transferred among unrelated bacteria. Ref: katzung 12th ed INtroduction to chemotherapy.', 'role': 'assistant'}]