This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Bacteriology, Subject name: Microbiology
[{'content': 'Lepra bacilli are best cultured in \nSelect and explain. \nA. Armadillos, B. Mouse foot pad, C. Guinea pigs, D. Rabbit testes', 'role': 'user'}, {'content': "Answer: B \nExplanation: Footpad of mouse: lepra bacilli multiply in the footpad of mice kept at a low temperature (20 deg). This has become the standard procedure for experimental work with the bacillus. Following intradermal injection into the footpad of mice, a granuloma develops at the site in 1-6 months. If cell-mediated immunity is suppressed by thymectomy or the administration of an anti-lymphocyte serum, generalised infection is produced, simulating lepromatous leprosy. Ref: Textbook of microbiology; Ananthanarayan and paniker's; 10th edition; Pg: 372", 'role': 'assistant'}]