Which of the following characters are common to both Annelida and Chordata?
a) coelom
b) bilateral symmetry
c) pharyngeal gill-slits
d) organ system level
e) metamerism
f) post-anal tail
Coelom, organ system level of organisation, bilateral symmetry and metamerism are the characters shared both by annelids and chordates.
Post-anal tail and pharyngeal gill-slits are found only in chordates (not in non-chordates like annelids).