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 is true about salmonella gastroenteritis? 
Select and explain. 
A. Always associated with blood and mucus in stools, B. Is due to exotoxin, C. Mainly diagnosed by serological testing, D. None
D: None
Answer: D: None 
Explanation: Ans. is None In salmonella gasteroenteritis:- i) Diarrhea is nonbloody (option a is incorrect). ii) It is due to invasion of bowel mucosa, not toxin mediated (option b is incorrect). iii) It is diagnosed by isolation of organism from stools (option c is incorrect). iv) Fever is one of the commoner symptom (option d is incorrect).