Question: who led a mission to california in 1846
[{'answer': 'Lieutenant Colonel John C. Frémont', 'provenance': [{'wikipedia_id': '1166399', 'title': 'Californio', 'start_paragraph_id': 83, 'start_character': 112, 'end_paragraph_id': 83, 'end_character': 146, 'bleu_score': 1.0, 'section': 'Section::::History.:The Mexican–American War.\n'}]}, {'provenance': [{'wikipedia_id': '1166399', 'title': 'Californio', 'start_paragraph_id': 83, 'start_character': 0, 'end_paragraph_id': 83, 'end_character': 378, 'bleu_score': 0.96746874041754, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 10472742957567254668}, 'section': 'Section::::History.:The Mexican–American War.\n'}]}]