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': 'True about Diptheria - \nSelect and explain. \nA. Caused by Gram negative bacilli, B. Incubation period 2-5 days, C. Chemoprophylaxis is done with rifampicin, D. All', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Ans. is \'b\' i.e.,Incubation period 2-5 days . Diptheria is caused by Gram positive bacilli, Corynebacterium diphtheriae . Incubation period of most common form of diphtheria ( faucial/ tonsiliopharyngeal diphtheria) is 2-5 days. . For chemoprophylaxis erythromycin or penicillin are used. " Previously immunized asymptomatic household contact should receive booster dose of diphtheria toxoid. Those not fully immunized but asymptomatic contacts should receive immunization for their age".---0.P. Ghai 7th/221 "Lifelong immunity is usually, but not always, acquired after disease or inapparent infection"---health.vic.gov.au> IDAES home > blue book . So, child recovered from illness is already is immune. No active immunization is required.', 'role': 'assistant'}]