Question: which part of the mcs produces the bow echo on radar
[{'answer': 'the rear of the system', 'provenance': [{'wikipedia_id': '2591641', 'title': 'Bow echo', 'start_paragraph_id': 5, 'start_character': 581, 'end_paragraph_id': 5, 'end_character': 603, 'bleu_score': 1.0, 'section': 'Section::::Formation.\n'}]}, {'provenance': [{'wikipedia_id': '2591641', 'title': 'Bow echo', 'start_paragraph_id': 5, 'start_character': 0, 'end_paragraph_id': 5, 'end_character': 722, 'bleu_score': 0.985662154730604, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 13182591354999294006}, 'section': 'Section::::Formation.\n'}]}]