B

Rinsing the root surface gently with sterile saline preserves viable periodontal-ligament cells and removes debris before immediate re-implantation; scrubbing or sterilizing the root destroys these cells and worsens prognosis, and endodontic treatment is performed after replantation, not beforehand [Trope, 1995, PMID 7890110; Fouad et al., 2020 IADT Guidelines, PMID 32460393].