A 68-year-old woman presents with fatigue and exertional dyspnoea. FBC shows Hb 92 g/L, MCV 70 fL and low ferritin. She has no obvious gastrointestinal symptoms. What is the most appropriate next step in evaluation?AStart oral iron and review in 6 months without further investigationBArrange faecal occult blood testing onlyCArrange upper GI endoscopy onlyDArrange colonoscopy (and usually upper GI endoscopy) to investigate for occult gastrointestinal blood lossENo investigation is required because this is likely menopausalCheck my answer