Answer:
Protostomes undergo spiral and determinate cleavage in the early embryonic stages, and the coelom is formed through the process of schizocoely.
The mouth first develops from the blastopore, which is the first developmental opening.
Clams, snails, slugs, octopuses, earthworms, and are protostome coelomates, meaning they are formed from head to foot (or mouth to foot).
Step-by-step explanation: