Question: who plays as batman in batman vs superman
[{'answer': 'Ben Affleck', 'provenance': [{'wikipedia_id': '2619910', 'title': 'Batman v Superman: Dawn of Justice', 'start_paragraph_id': 1, 'start_character': 356, 'end_paragraph_id': 1, 'end_character': 367, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '2619910', 'title': 'Batman v Superman: Dawn of Justice', 'start_paragraph_id': 12, 'start_character': 0, 'end_paragraph_id': 12, 'end_character': 47, 'bleu_score': 0.6803749333171201, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 18235839194947289903}, 'section': 'Section::::Cast.\n'}]}]