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
"Eleks" test is for: 
Select and explain. 
A. Influenza, B. Diptheria, C. Brucella, D. Cholera
B: Diptheria
Answer: B: Diptheria 
Explanation: Diptheria