Question: when did the titanic set sail from belfast
[{'answer': 'April 1912', 'provenance': [{'wikipedia_id': '19285924', 'title': 'RMS Titanic', 'start_paragraph_id': 3, 'start_character': 32, 'end_paragraph_id': 3, 'end_character': 42, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '19285924', 'title': 'RMS Titanic', 'start_paragraph_id': 71, 'start_character': 0, 'end_paragraph_id': 71, 'end_character': 875, 'bleu_score': 0.9578445359288791, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 13413349799465171315}, 'section': 'Section::::Building and preparing the ship.:Sea trials.\n'}]}]