Question: who wrote against animal experimentation with his book animal liberation
[{'answer': 'Peter Singer', 'provenance': [{'wikipedia_id': '441835', 'title': 'Animal Liberation (book)', 'start_paragraph_id': 1, 'start_character': 102, 'end_paragraph_id': 1, 'end_character': 114, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '441835', 'title': 'Animal Liberation (book)', 'start_paragraph_id': 1, 'start_character': 0, 'end_paragraph_id': 1, 'end_character': 705, 'bleu_score': 0.8978110061854281, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 2181986191737026711}, 'section': 'Section::::Abstract.'}]}]