General Medicine General be90a273 28 year old G3 P2 at 16 weeks gestation reports extreme fatigue and her hemoglobin concentration is 7.5g / dL MCV is markedly elevated and measures 12.4 fL. Her peripheral blood smear is shown below. What is most likely etiolgy A Iron deficiency B Vitamin B6 deficiency C Folic acid deficiency D Vitamin B12 deficiency