A student observed a laboratory specimen with the following features.
a.    The body is elongated and worm-like.
b.    The body can be divided into identical left and right halves in only one plane.
c.    The body surface is distinctly marked out into segments.
d.    Each segment has a pair of lateral appendages.
The specimen should be identified as

 

• A

  Pheretima

• B

  Ascaris

• C

  Pila

• D

  Nereis