With Regard to the Obsessions Seen in Patients with Obsessive-Compulsive

With regard to the obsessions seen in patients with obsessive-compulsive disorder,what does the term "need for symmetry" refer to?

A) the need to put everything on one's right and nothing on the left
B) the need to keep things in perfect order
C) the need to do something a number of different ways
D) the need to touch some things before others