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: Microbiology
[{'content': 'Which of the following is the main colonizer of sebaceous gland - \nSelect and explain. \nA. Propionic bacterium acnes, B. Diptheria, C. Strep.pyogens, D. Staph. aureus', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Propionibacterium acnes are the commonest agent causing acne in teenagers as it has affinity for sebaceous glands.\nLesions in acne develop with in the sebaceous follicle.', 'role': 'assistant'}]