If You Wanted to Identify an Unfamiliar Protostome with a Limbless

If you wanted to identify an unfamiliar protostome with a limbless, wormlike body, which characteristic would not be helpful in differentiating one species from another?

A) what kind of mouthparts the organism had
B) whether the organism metamorphosed into a different form
C) whether the organism's body was divided into segments
D) whether the organism moved using a hydrostatic skeleton