Question

question 19 of 25
which type of organism developed first?
a. vertebrates
b. chordates
c. deuterostomes
d. sponges

Explanation:

Sponges (Porifera) are among the earliest multicellular organisms to evolve, appearing in the fossil record much earlier than vertebrates, chordates, or deuterostomes. Vertebrates are a sub - group of chordates, and deuterostomes include more complex organisms that evolved later than sponges.

Answer:

D. Sponges