What would be the best question to ask a client in order to make a differential diagnosis between obsessive-compulsive disorder (OCD) and hoarding disorder? a. Do you experience your family of origin as having a high degree of hoarding behaviours? b. At what age did you begin to experience your hoarding behaviours as distressing? c. Do you experience a compulsion to clean or contaminate everything that you hoard? d. Do you experience a high degree of difficulty discarding or parting with your possessions?