Answer: A

Reasoning: Histologic studies show that the supracrestal connective-tissue seal around osseointegrated implants averages about 1.0–2.5 mm. In canine models, mean connective-tissue contact was ≈1.3 mm [Cochran 1997, PMID 9058338], while human specimens have reported 1.6 mm in the mandible and 2.5 mm in the maxilla [Romanos 2010, PMID 20059419]. The only option that brackets this 1–2.5 mm span is 2–3 mm, making option A the closest and most accurate choice.