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: Medicine
An inoculum size of 10-100 bacteria or cysts can produce infection in all except : 
Select and explain. 
A. Shigella, B. Enterohemorrhagic Escherichia coli, C. Giardia lamblia, D. Vibrio cholerae
D: Vibrio cholerae
Answer: D: Vibrio cholerae 
Explanation: For Shigella, enterohemorrhagic Escherichia coli, Giardia lamblia, or Entamoeba, 10-100 bacteria or cysts can produce infection, while 1,00,000-10,00,00,000 Vibrio cholerae organisms must be ingested to cause disease. Reference: Harrisons Principles of Internal Medicine, 18th Edition, Page 1084