Which of the following pairs is an incorrect match?

The correct answer is option (4) as it represents an incorrect match because platyhelminthes are triploblastic organisms; not diploblastic. Option (1) represents the correct match as annelids and arthropods exhibit bilateral symmetry. Option (2) represents the correct match as sponges are acoelomates. Option (3) represents the correct match as coelenterates and ctenophores exhibit radial symmetry. Hence, option (1), (2) and (3) cannot be the answer.