Question: process of removing an element from stack is called
[{'answer': 'pop', 'provenance': [{'wikipedia_id': '273993', 'title': 'Stack (abstract data type)', 'start_paragraph_id': 5, 'start_character': 96, 'end_paragraph_id': 5, 'end_character': 99, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '273993', 'title': 'Stack (abstract data type)', 'start_paragraph_id': 5, 'start_character': 0, 'end_paragraph_id': 5, 'end_character': 552, 'bleu_score': 0.9808590314834971, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 1723628897789650499}, 'section': 'Section::::Abstract.'}]}]