Which was larger, the Abbasid Caliphate or the Mongol Empire?
{'directed': True, 'multigraph': False, 'graph': {}, 'nodes': [{'type': 'QUESTIONS_ENTITY', 'name_': 'Q12536', 'id': 0, 'label': 'Abbasid Caliphate'}, {'type': 'ANSWER_CANDIDATE_ENTITY', 'name_': 'Q12557', 'id': 1, 'label': 'Mongol Empire'}, {'type': 'INTERNAL', 'name_': 'Q193325', 'id': 2, 'label': 'Merv'}], 'links': [{'name_': 'P131', 'source': 2, 'target': 0, 'label': 'located in the administrative territorial entity'}, {'name_': 'P131', 'source': 2, 'target': 1, 'label': 'located in the administrative territorial entity'}]}