3. Jellyfish...
A ...have no single centralized brain.
Correct!
B ...are in the phylum Chordata.
Jellyfish are in the phylum Cnidaria.
C ...feed only on phytoplankton.
Jellyfish eat shrimp copepods, fish larvae and eggs and zooplankton.
D ...are in the family Monodontidae.
Jellyfish belong to the family Cyaneidae.
