A 40-year-old women presents with hepatic failure, greenish brown deposits in Descemet's membrane of cornea and chureiform movements. The defect most likely responsible for the patient's disease is -

• A. Defect synthesis of alpha 1 antitrypsin
• B. Defect of excretion of copper into bile
• C. An abnormality in glycogen synthesis
• D. Excessive absorption of iron from small bowel