Question: along the hpa-axis what is what factor is the first to be released in response to stress
[{'answer': 'cortisol', 'provenance': [{'wikipedia_id': '191003', 'title': 'Hypothalamic–pituitary–adrenal axis', 'start_paragraph_id': 9, 'start_character': 546, 'end_paragraph_id': 9, 'end_character': 554, 'bleu_score': 1.0, 'section': 'Section::::Anatomy.\n'}]}, {'provenance': [{'wikipedia_id': '191003', 'title': 'Hypothalamic–pituitary–adrenal axis', 'start_paragraph_id': 31, 'start_character': 0, 'end_paragraph_id': 31, 'end_character': 855, 'bleu_score': 0.9671679735406701, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 5209547977240904520}, 'section': 'Section::::Stress.:Stress and disease.\n'}]}]