C

Each gram of hemoglobin can bind about 1.34 mL of O₂ when fully saturated. Therefore, a blood hemoglobin concentration of 14 g/dL can carry 14 g/dL × 1.34 mL O₂/g ≈ 18–19 mL O₂ per 100 mL of blood, which matches option C (18). [Mairbäurl & Weber, 2012, PMID 23798307]