What city was administrative political and military center of the Inca Empire?
{'directed': True, 'multigraph': False, 'graph': {}, 'nodes': [{'type': 'QUESTIONS_ENTITY', 'name_': 'Q28573', 'id': 0, 'label': 'Inca Empire'}, {'type': 'ANSWER_CANDIDATE_ENTITY', 'name_': 'Q5218', 'id': 1, 'label': 'Quechua'}], 'links': [{'name_': 'P37', 'source': 0, 'target': 1, 'label': 'official language'}]}