Four of the Following Describe a Bilaterally Symmetrical Animal

Question

Four of the following describe a bilaterally symmetrical animal.Which one is the exception?  
A) It has left and right sides.
B) It usually displays cephalization.
C) It produces mirror images regardless of the number of "cuts" through the central axis.
D) It usually has a three layer body plan.
E) It can be a deuterostome.

Accepted Answer

Bilaterally symmetrical animals produce mirror images only with one plane of symmetry (down the central axis). If the animal is cut along any other plane, the resulting pieces are not mirror images of each other.