Question: when was celibacy introduced in the catholic church
[{'answer': 'in the fourth - century', 'provenance': [{'wikipedia_id': '8795944', 'title': 'Clerical celibacy in the Catholic Church', 'start_paragraph_id': 16, 'start_character': 160, 'end_paragraph_id': 16, 'end_character': 189, 'bleu_score': 1.0, 'section': 'Section::::Historical origins.\n'}]}, {'provenance': [{'wikipedia_id': '8795944', 'title': 'Clerical celibacy in the Catholic Church', 'start_paragraph_id': 16, 'start_character': 0, 'end_paragraph_id': 16, 'end_character': 347, 'bleu_score': 0.923768200931469, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 3683865233529438461}, 'section': 'Section::::Historical origins.\n'}]}]