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
Not true about vibrio cholera is 
Select and explain. 
A. Increase water and sodium loss by debilitating diarrhoea, B. Toxic protein is cholera toxin, C. Activate adenylatecyclase, D. Gram positive rod
D: Gram positive rod
Answer: D: Gram positive rod 
Explanation: None