Gram Positive Cocci
The most common agent associated with neonatal bacterial meningitis is (AIIMS Nov 2009)
Streptococcus agalactiae Ref : NELSON 18th Ed Chapter 109.
b. S. pneumoniae, other streptococci, non-typable Haemophilus influenzae, both coagulase-positive and coagulase-negative staphylococci, Klebsiella, Enterobacter, Pseudomonas, T. pallidum, and Mycobacterium tuberculosis may also produce meningitis.
c. Whereas GHAI 7th Ed states E.coli as the most common cause.
d. In the absence of E.coli as an option the answer is definitely GBS.