The Placement of the Phylum Platyhelminthes in the Phylogenetic Tree

The placement of the phylum Platyhelminthes in the phylogenetic tree differs between a morphologically based phylogeny and a molecular based phylogeny.How do scientists best differentiate the interpretation based on molecular phylogeny?

A) Modern Platyhelminthes do not have a coelom but did originate from an ancestor that had one.
B) The Platyhelminthes clade separated from other clades before coeloms evolved and consequently Platyhelminthes have never had a coelom.
C) Platyhelminthes originated from ancestors with a coelom and have retained it to the present time.
D) Platyhelminthes evolved from an ancestor without a coelom but developed one during the course of their evolution.
E) Some Platyhelminthes have a coelom but others do not and it is difficult to conclude anything about its evolution within the cladE.