Ryan is an 11-year-old child who loves to arrange his room a…

Ryаn is аn 11-yeаr-оld child whо lоves to arrange his room and put all his things in order. If that has already been done, he sets about cleaning it all over again, never seeming to tire of it. His parents have a hard time convincing him that his room is indeed clean and ordered. Ryan's condition is most indicative of ________ disorder.