A 47-year-old female is brought to the emergency department with complaints of malaise, nausea and vomiting, and fatigue. The patient reveals a long history of alcohol abuse for the last 10 years requiring drinks daily especially in the morning an “eye opener.” she has been to rehab on several occasions for alcoholism but has not been able to stop drinking. She is currently homeless and jobless. She denies cough, fever, chills, upper respiratory symptoms, sick contacts, recent travel, hematemesis, or abdominal pain. She reports feeling hungry and has not eaten very well in a long time. On physical exam she appears malnourished but in no distress. Her physical exam is normal. Her blood count reveals a normal white blood cell count but does show an anemia with large red blood cells. Her amylase, lipase, and liver function tests were normal. What is the most likely cause of her anemia? What is the molecular basis for the large erythrocytes?