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: Pediatrics
Haemophilus influenzae has been isolated from the CSF of a two year old boy suffering from meningitis. The strain is beta-lactamase producing and resistant to chloramphenicol. The most appropriate antimicrobial in such a situation is: 
Select and explain. 
A. Trimethoprim-sulphamethoxazole combination, B. Ciprofloxacin, C. Third-generation cephalosporin, D. Vancomycin
C: Third-generation cephalosporin
Answer: C: Third-generation cephalosporin 
Explanation: If isolate is resisatnt to ampicillin, extended spectrum cephalosporins such as cefotaxime or ceftriaxone are used. Ref: Harrison's Principles of Internal Medicine, 17th Edition, Page 923 ; Text Book of Pediatrics By Nelson, 17th Edition, Pages 2042, 7905