Answer: I think it’s D. Pls don’t bash me if it’s wrong
The red dot is filled. The other red dot is filled because
Both use oxygen, both produce energy, both give out carbon dioxide as the result and the overall chemical reactions are the same.
Hope this helps :)
If I'm not mistaken, it leaves through the osculum which is a cavity located on the upper part of a sponge.
Sponges feed through a process called filtration, which means that they filter the water in search of nutrients. And after they collect everything they need from the water, they need to let it out somehow; through the osculum.
Hope it helped,
BioTeacher101