Question: who are the defending champions of champions trophy
[{'answer': 'Pakistan', 'provenance': [{'wikipedia_id': '769640', 'title': 'ICC Champions Trophy', 'start_paragraph_id': 5, 'start_character': 508, 'end_paragraph_id': 5, 'end_character': 516, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}]