| Column I | Column II | ||
| A. | Porifera | P | Metagenesis |
| B. | Cnidaria | Q | Flame cells |
| C. | Ctenophora | R | Comb Plates |
| D. | Platyhelminthes | S | Choanocyte |
| A | B | C | D | |
| 1. | R | Q | S | P |
| 2. | S | P | R | Q |
| 3. | P | S | Q | R |
| 4. | Q | R | P | S |
Parazoa is a taxon at the base of the phylogenetic tree of the animal kingdom and includes the most primitive forms, characterized by not having proper tissues. The phylum/phyla included in this taxon will be:
| I. Porifera | II. Cnidaria | III. Ctenophora |
| 1. | Only I | 2. | Only II and III |
| 3. | Only I and II | 4. | I, II and III |