 Which group of people shares the most similarities with the group of patients in the mental institution, as they are described by the author?
Illustrated by Freas Miss Abercrombie, the manual therapist patted the old man on the shoulder. Through the barred windows of the workshop, rolling green hills were seen, their tree-studded flanks making a pleasant setting for the mental institution. The crafts building was a good mile away from the main buildings of the hospital and the hills blocked the view of the austere complex of buildings that housed the main wards. The sun set, darkness fell over the stilled hospital grounds and the ward lights winked out at nine o'clock, leaving just a single light burning in each ward office. At 5:30 a.m., a plane landed at a nearby airfield and a platoon of Atomic Energy Commission experts, military intelligence men, four FBI agents and an Army full colonel disembarked.
 A Kindergarten class
 A circus troupe  A disorderly mob  An artists' collective  A Kindergarten class