Question: what is the name of the main canine character in jack london call of the wild
[{'answer': 'Buck', 'provenance': [{'wikipedia_id': '358335', 'title': 'The Call of the Wild', 'start_paragraph_id': 1, 'start_character': 238, 'end_paragraph_id': 1, 'end_character': 242, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '358335', 'title': 'The Call of the Wild', 'start_paragraph_id': 1, 'start_character': 0, 'end_paragraph_id': 1, 'end_character': 647, 'bleu_score': 0.9832621206481431, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 5072118111953322868}, 'section': 'Section::::Abstract.'}]}]