This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Bacteria, Subject name: Microbiology
A 1-week-old neonate presents to the pediatric emergency room with fever, irritability, poor feeding, and a bulging anterior fontanelle. Lumbar puncture is performed, and the cerebrospinal fluid (CSF) grows group B Streptococcus. Which of the following is the most likely pathogenic mechanism? 
Select and explain. 
A. Complement C5a, a potent chemoattractant, activates polymorphonuclear neutrophils (PMNs), B. In the absence of a specific antibody, opsonization, phagocyte recognition, and killing do not proceed normally, C. The alternative complement pathway is activated, D. The streptococci are resistant to penicillin
B: In the absence of a specific antibody, opsonization, phagocyte recognition, and killing do not proceed normally
Answer: B: In the absence of a specific antibody, opsonization, phagocyte recognition, and killing do not proceed normally 
Explanation: There has been speculation concerning the pathogenesis of GBS. This includes failure to activate complement pathways and immobilization of polymorphonuclear leukocytes due to the inactivation of complement C5a, a potent chemoattractant.