Question: who is the actor who plays denny on grey's anatomy
[{'answer': 'Jeffrey Dean Morgan', 'provenance': [{'wikipedia_id': '4998900', 'title': 'Jeffrey Dean Morgan', 'start_paragraph_id': 0, 'start_character': 0, 'end_paragraph_id': 0, 'end_character': 19, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}]