<prompt> Which of the following statements differentiates Obsessional idea from delusion:Obsessional idea is not a conventional beliefObsessional idea is held in spite of evidence to the contraryObsessional idea is regarded as senseless by patientObsessional idea is held on inadequate ground  <response>: Obsessions are considered senseless by the patient whereas patient has full belief in the delusions. For example, a patient who gets obsessive thoughts that his hands are unclean understands that his thought is not true and gets bothered by this repetitive thought whereas a patient with delusion of infidelity actually believes that his wife is cheating on him and continues to believes so irrespective of what others say. 