A 64-year-old woman presents with fatigue and exertional dyspnoea. Hb is 92 g/L, MCV 72 fL, ferritin 6 µg/L, and transferrin saturation is low. She has no overt bleeding but is postmenopausal. What is the most appropriate next step in management?AStart oral iron supplementation and no further investigationBStart folic acid supplementationCRefer for urgent gastroenterological evaluation for possible occult blood lossDOrder serum B12 only and delay other investigationsEReassure that this is likely dietary and observeCheck my answer