Answer:
b. Space for complex organ systems
Explanation:
Coelom can be defined as a fluid-filled body cavity with mesoderm lining, one of the germ leaflets. In triblastic animals, there may or may not be coelom. Those who have the cavity have the advantage of using this cavity to store complex internal organs (viscera). When there is no coelom, animals are said to be aceloma, like the flat-body worms - the flatworms.
This cavity is formed during embryonic development and is related to several important functions, such as excreta elimination, temporary gamete deposition, distribution of substances throughout the body, accommodation of internal organs and, in some animals, it also functions as a support.
