Question: who played alex p keaton on family ties
[{'answer': 'Michael J. Fox', 'provenance': [{'wikipedia_id': '2565169', 'title': 'Alex P. Keaton', 'start_paragraph_id': 1, 'start_character': 384, 'end_paragraph_id': 1, 'end_character': 398, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '2565169', 'title': 'Alex P. Keaton', 'start_paragraph_id': 1, 'start_character': 0, 'end_paragraph_id': 1, 'end_character': 591, 'bleu_score': 0.9788329837059241, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 8467254800563056722}, 'section': 'Section::::Abstract.'}]}]