6 A 42-year-old woman with a chronic cough has a positive tuberculin skin test result. A chest radiograph shows severalcavitary lesions in the right upper lobe. The woman is given isoniazid therapy. On physical examination 6 months later, a peripheral neuropathy is observed. Administration of which of the following with isoniazid would most likely have prevented the neuropathy? (A) Ascorbic acid (B) Calcium (C) Cobalamin (vitamin B12) (D) Folate (E) Niacin (F) Pyridoxine (G) Riboflavin pathology