Which of the following situations would most likely lead to a stable
population size?
O
A. The birthrates and death rates were higher than the rates of
immigration and emigration
O
B. The rates of birth and immigration were lower than the rates of
death and emigration
O
C. The rates of birth and immigration were balanced by the rates of
death and emigration
O
D. The rates of birth and immigration were higher than the rates of
death and emigration

C. The rates of birth and immigration were balanced by the rates of  death and emigration .

Explanation:

A stable population size means that, over the years, number of individuals doesn't change significantly. This condition is only possible when the birth rate and immigration rate is balanced with the death rate and emigration rate. In this scenario, population size would not change much.

On the other hand, if a birth rate and immigration rate will increase, the population size in any area would be increased. This typically happens in growing cities. By contrast, if death rate and emigration rate increases, the size of population will decrease. This happens mostly in rural areas.

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.