Question: who has conceded the least goals in the world cup 2018
[{'answer': 'Denmark', 'provenance': [{'wikipedia_id': '57682452', 'title': '2018 FIFA World Cup statistics', 'start_paragraph_id': 10, 'start_character': 120, 'end_paragraph_id': 10, 'end_character': 127, 'bleu_score': 1.0, 'section': 'Section::::Squads.:Coaches.\n'}]}, {'answer': 'Iran', 'provenance': [{'wikipedia_id': '57682452', 'title': '2018 FIFA World Cup statistics', 'start_paragraph_id': 18, 'start_character': 134, 'end_paragraph_id': 18, 'end_character': 138, 'bleu_score': 1.0, 'section': 'Section::::Squads.:Players.\n'}]}, {'answer': 'Peru', 'provenance': [{'wikipedia_id': '57682452', 'title': '2018 FIFA World Cup statistics', 'start_paragraph_id': 9, 'start_character': 99, 'end_paragraph_id': 9, 'end_character': 103, 'bleu_score': 1.0, 'section': 'Section::::Squads.:Coaches.\n'}]}]