Question: what does hd stand for on chevy trucks
[{'answer': 'heavy - duty', 'provenance': [{'wikipedia_id': '865369', 'title': 'Chevrolet C/K', 'start_paragraph_id': 60, 'start_character': 218, 'end_paragraph_id': 60, 'end_character': 235, 'bleu_score': 1.0, 'section': 'Section::::Third generation 1973–1987.:Chassis and powertrain.\n'}]}, {'provenance': [{'wikipedia_id': '865369', 'title': 'Chevrolet C/K', 'start_paragraph_id': 1, 'start_character': 101, 'end_paragraph_id': 1, 'end_character': 818, 'bleu_score': 0.79256210270849, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 8409116483083123970}, 'section': 'Section::::Abstract.'}]}]