When organisms moves out of a population

Migration is the movement of individual organisms into, or out of, a population. Migration affects population growth rate. There are two types of migration: Immigration is the movement of individuals into a population from other areas.

Explanation:

b

is correct hope this   also i learnd this in middle school

organisms that lack symmetry are called asymmetrical and belong to phylum porifera/sponges.

organisms with specialized stinging cells belong to phylum cnidaria. stinging cells are called cnidoblast cells.

cnidarians show two morphological forms : polyp (sessile) and medusa (mobile)

filter feeding is observed in porifera members.  

alternation of generation is observed in coelenterata or cnidaria. there is alternation of asexual polyp form and sexual medusoid form. it is also referred as metagenesis.