This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Chemotherapy, Subject name: Pharmacology
[{'content': 'Amphotericin-B is obtained from: \nSelect and explain. \nA. Streptomyces nodosus, B. Streptomyces pimprina, C. Streptomyces nousseri, D. Streptomyces fragilis', 'role': 'user'}, {'content': 'Answer: A \nExplanation: POLYENE ANTI BIOTICS The name polyene is derived from their highly double-bonded structure. Amphotericin B is described as the prototype. Amphotericin B (AMB): It is obtained from Streptomyces nodosus ESSENTIALS OF MEDICAL PHARMACOLOGY K.D.TRIPATHI SIXTH EDITION PAGE NO:757', 'role': 'assistant'}]