B

With appropriate prophylactic antibiotics, surgical-site infection rates for clean-contaminated (class II) operations fall to only a few percent—well below 10% (e.g., 0.6% in a large U.S. cohort and 2.8% in a Yemeni series) [Classen 1992, PMID 1728731; Raja'a 2002, PMID 12070545].