This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Infection, Subject name: Medicine
A 30-year-old pregnant woman develops severe sepsis with headache and neck stiffness after eating coleslaw, soft cheese, and cantaloupes at a potluck dinner. Two other women who attended the event develop self-limiting abdominal cramps, nausea, and vomiting. select appropriate infectious agent. 
Select and explain. 
A. Herpes simplex virus, B. Epstein-Barr virus, C. Parvovirus B19, D. Listeria monocytogenes
D: Listeria monocytogenes
Answer: D: Listeria monocytogenes 
Explanation: Listeriosis is caused by eating food contaminated with L monocyto-genes. It is a gram-positive rod that has a predilection to infect older adults, pregnant women, immunocompromised patients, and newborns. It can cause sepsis, meningitis, and miscarriages. Deli meats, unwashed vegetables, raw milk, soft cheeses, and cantaloupes have been implicated in causing Listeria outbreaks. Ampicillin is the antibiotic of choice for treating this infection.