Question: who has propounded the two factor theory of motivation
[{'answer': 'Frederick Herzberg', 'provenance': [{'wikipedia_id': '649939', 'title': 'Two-factor theory', 'start_paragraph_id': 1, 'start_character': 315, 'end_paragraph_id': 1, 'end_character': 333, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '649939', 'title': 'Two-factor theory', 'start_paragraph_id': 1, 'start_character': 0, 'end_paragraph_id': 1, 'end_character': 333, 'bleu_score': 0.771853481978062, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 14440058302822503771}, 'section': 'Section::::Abstract.'}]}]