One Reason Why the Checking Rituals of Certain Obsessive-Compulsive People

Multiple Choice

One reason why the checking rituals of certain obsessive-compulsive people go on for so long is that

A) the ritual is an automatic reflex.
B) such people do not trust their memory of whether they have completed the ritual.
C) such people experience the ritual itself as an intense sensory pleasure.
D) such people have a very poor memory of what they have or have not actually done.