Question: who gave the address to the nation on the challenger disaster in january 1986
[{'answer': 'President Ronald Reagan', 'provenance': [{'wikipedia_id': '403717', 'title': 'Space Shuttle Challenger disaster', 'start_paragraph_id': 3, 'start_character': 158, 'end_paragraph_id': 3, 'end_character': 181, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '403717', 'title': 'Space Shuttle Challenger disaster', 'start_paragraph_id': 66, 'start_character': 0, 'end_paragraph_id': 66, 'end_character': 583, 'bleu_score': 0.6479159361325351, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 8291872641722254034}, 'section': 'Section::::Aftermath.:White House response.\n'}]}]