Question: which type of wave requires a medium for transmission
[{'answer': 'Sound', 'provenance': [{'wikipedia_id': '41812', 'title': 'Transmission medium', 'start_paragraph_id': 3, 'start_character': 307, 'end_paragraph_id': 3, 'end_character': 312, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'answer': 'mechanical waves', 'provenance': [{'wikipedia_id': '41812', 'title': 'Transmission medium', 'start_paragraph_id': 3, 'start_character': 429, 'end_paragraph_id': 3, 'end_character': 445, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'answer': 'heat energy', 'provenance': [{'wikipedia_id': '41812', 'title': 'Transmission medium', 'start_paragraph_id': 3, 'start_character': 450, 'end_paragraph_id': 3, 'end_character': 461, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '41812', 'title': 'Transmission medium', 'start_paragraph_id': 3, 'start_character': 0, 'end_paragraph_id': 3, 'end_character': 846, 'bleu_score': 0.9844346099707091, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 16562540726535161930}, 'section': 'Section::::Abstract.'}]}]