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: Social & Preventive Medicine
Non immunized susceptible diphtheria contacts should receive: 
Select and explain. 
A. Erythromycin, B. Penicillin and diphtheria antitoxin, C. Penicillin, diphtheria antitoxin and DPT vaccine, D. No treatment is required
C: Penicillin, diphtheria antitoxin and DPT vaccine
Answer: C: Penicillin, diphtheria antitoxin and DPT vaccine 
Explanation: Non immunized contacts should receive prophylactic penicillin or erythromycin. They should also be given 1000 to 2000 units of antitoxin and actively immunized against diphtheria. Ref: Park 21st edition, page 151.