Question: how many episodes in line of duty season 3
[{'answer': '6', 'provenance': [{'wikipedia_id': '50402887', 'title': 'List of Line of Duty episodes', 'start_paragraph_id': 1, 'start_character': 125, 'end_paragraph_id': 1, 'end_character': 126, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}]