Question: Which choir collaborated on a mix tape that was produced among others by the group The Social Experiment and that featured the song "Angels"?
{'answer': "Chicago Children's Choir", 'supporting_facts': [['Angels (Chance the Rapper song)', 0], ['Angels (Chance the Rapper song)', 1], ['Angels (Chance the Rapper song)', 2], ['Coloring Book (mixtape)', 0], ['Coloring Book (mixtape)', 1], ['Coloring Book (mixtape)', 2]]}