After treatment of pneumonia, a child developed pseudomembranous colitis. Which of the following drug frequently causes pseudomembranous colitis?

Alteration of the normal enterocolonic bacterial flora by prior antibiotic administration is required for the development of C difficile colitis in the large majority of those who develop the disease. Antibiotics most often associated with C difficile-induced disease include aminopenicillins, fluoroquinolones, cephalosporins, and clindamycin. Also cancer chemotherapy or preexisting IBD, especially with colonic involvement, appears to trigger C difficile colitis. Oral metronidazole or vancomycin should be given and fluids replaced. Ref: Trier J.S. (2012). Chapter 5. Acute Diarrheal Disorders. In N.J. Greenberger, R.S. Blumberg, R. Burakoff (Eds), CURRENT Diagnosis & Treatment: Gastroenterology, Hepatology, & Endoscopy, 2e.