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
Which of the following is true of cholera- 
Select and explain. 
A. Recent epidemic was due to classical type, B. Causes secretory diarrhoea, C. Caused by endotoxin, D. Vibriocidal antibodies correspond to susceptibility
B: Causes secretory diarrhoea
Answer: B: Causes secretory diarrhoea 
Explanation: Vibrio causes secretory diarrhea.

About Other options:

Recent epidemics are due to O1 ElTor and also O139 serovar. (Classical still exists and few cases were reported from Bangladesh)
Vibriocidal antibodies in serum (titer 1:20) have been associated with protection against colonization and disease. …………… Jawetz 25/e p237
Endotoxin (LPS) does not play any role in pathogenicity of cholera but is responsible for immunity developed by killed vaccine.