Question: who was a in pretty little liars episode
[{'answer': 'Mona Vanderwaal', 'provenance': [{'wikipedia_id': '38061693', 'title': 'A (Pretty Little Liars)', 'start_paragraph_id': 2, 'start_character': 24, 'end_paragraph_id': 2, 'end_character': 39, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'answer': 'CeCe Drake', 'provenance': [{'wikipedia_id': '38061693', 'title': 'A (Pretty Little Liars)', 'start_paragraph_id': 2, 'start_character': 71, 'end_paragraph_id': 2, 'end_character': 81, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'answer': 'Sara Harvey', 'provenance': [{'wikipedia_id': '38061693', 'title': 'A (Pretty Little Liars)', 'start_paragraph_id': 2, 'start_character': 509, 'end_paragraph_id': 2, 'end_character': 520, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'answer': 'Alex Drake', 'provenance': [{'wikipedia_id': '38061693', 'title': 'A (Pretty Little Liars)', 'start_paragraph_id': 2, 'start_character': 768, 'end_paragraph_id': 2, 'end_character': 778, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '38061693', 'title': 'A (Pretty Little Liars)', 'start_paragraph_id': 2, 'start_character': 0, 'end_paragraph_id': 2, 'end_character': 806, 'bleu_score': 0.90038033551032, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 13602192166770722852}, 'section': 'Section::::Abstract.'}]}]