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
A 28-year-old lady presented with, headache, kernigs sign positive, culture showed gram positive bacilli, most probable organism is: 
Select and explain. 
A. Listeria monocytogenes, B. H. influenza, C. Meningococci, D. Streptococcus pneumoniae
A: Listeria monocytogenes
Answer: A: Listeria monocytogenes 
Explanation: Ans. (a) i.e. Listeria monocytogenes Among options provided listeria is the only Gr positive bacilli. Listeria accounts for 10% of cases of community acquired bacterial meningitis. For details see previous answers.