The biodiversity of different taxa is often represented as a tree similar to the one shown in the diagram.
According to this diagram, to which phylum is Chordata most similar?
a
Arthropoda because they are at similar heights on the tree and may share a common ancestor
b
Nematoda because they are on the same branch of the tree and may have similar bone structures
c
Mollusca because they are closest together on the tree and may share many similarities in their DNA
d
Echinodermata because they are close together on the same branch of the tree and may have common features