This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Lab Investigations, Subject name: Microbiology
A 3 week old child presented to the pediatrician with meningitis. A presumptive diagnosis of late onset perinatal meningitis was made. The CSF culture was positive for gram positive bacilli. Which of the following characteristic of this bacteria would be helpful in differentiating it from other bacterial agents:- 
Select and explain. 
A. Ability to grow on blood agar, B. Ability to produce catalase, C. Fermentative attack on sugars, D. Motility at 25 degree Celsius.
D: Motility at 25 degree Celsius.
Answer: D: Motility at 25 degree Celsius. 
Explanation: L. monocytogenes is resposible for late onset perinatal meningitis. gram positive, non -spore forming rod tumbling motility at 22-28 degree Celsius but not at 37 degree Celsius- differentiates listeria from diphtheroids that are members of the normal microbiota of the skin.