I think that this question was asked by a bot made by brainly.
If you're asking for PLATO, I think the answer is "Four fused rings of carbon".
Protein is the type of macromecule that primarily make-up muscle cells. Protein is one of the most important macromolecule that serves as building blocks of any tissues that are found in different kinds of organisms. Aside from building, these proteins are also responsible for tissue repair.
Answer:
they cannot know their doing and there is a posiblity that they fail
B- Electron transport chain
