The answer is a simple radial nervous system.
Echinoderms do not have brains. Around their mouth, they have central rings from which nerves radially run into arms and along the body. Movement is controlled by the branches of those radial nerves.
All living organisms are made of only 20 different aminoacids- this is the correct answer! This means that the genetic code only codes for those 20 aminoacids (for example Glutamine and Lysine).
The 20 aminoacids that can form proteins are also called Proteinogenic amino acids.
I can infer that chimpanzees are more evolved than human but not as cats and dogs
B. is the correct answer I think
