Question: a severe vitamin b12 deficiency results in what form of anemia
[{'answer': 'pernicious', 'provenance': [{'wikipedia_id': '12742560', 'title': 'Vitamin B12 deficiency', 'start_paragraph_id': 2, 'start_character': 151, 'end_paragraph_id': 2, 'end_character': 161, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '12742560', 'title': 'Vitamin B12 deficiency', 'start_paragraph_id': 7, 'start_character': 0, 'end_paragraph_id': 7, 'end_character': 109, 'bleu_score': 0.6709293368821521, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 15640892714602671312}, 'section': 'Section::::Signs and symptoms.\n'}]}]