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
Investigation of choice for diphtheria carrier is: 
Select and explain. 
A. Throat swab culture, B. Gram’s stain, C. Albert’s stain, D. Ziehl Neelsen stain
A: Throat swab culture
Answer: A: Throat swab culture 
Explanation: Carriers can be detected only by cultural method.
Swab should be taken from both the nose and throat.