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
What is the recommended period of isolation for a suspected case of diphtheria? 
Select and explain. 
A. 7 days, B. 10 days, C. 12 days, D. 14 days
D: 14 days
Answer: D: 14 days 
Explanation: All suspected or confirmed cases and carriers of diphtheria should be isolated preferably in a hospital for at least 14 days or until proved free of infection by two consecutive nose and throat swabs taken 24 hours apa. Ref: Park 21st edition, page 150.