Question: where is the acl located in the leg
[{'answer': 'knee', 'provenance': [{'wikipedia_id': '578923', 'title': 'Anterior cruciate ligament', 'start_paragraph_id': 1, 'start_character': 139, 'end_paragraph_id': 1, 'end_character': 143, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '578923', 'title': 'Anterior cruciate ligament', 'start_paragraph_id': 1, 'start_character': 0, 'end_paragraph_id': 1, 'end_character': 570, 'bleu_score': 0.6730015346190691, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 5916804544395837540}, 'section': 'Section::::Abstract.'}]}]