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.
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<u>Appropriate</u><u> </u><u>Answer</u><u>:</u></h3>

Nucleus is the control centre of the cell and manages all the cellular activities taking place inside the cell. It consists of four parts :-
- Nuclear membrane,
- Nucleoplasm,
- Chromatin material and
- Nucleolus.
The Chromatin material(Condensed - Chromosome) stores the cell's DNA which is transmitted to next generation.
Your answer is Enamel it is the coating on teeth that helps prevent damage.
The correct answer is c.antipsychotic drugs.
<span>Drugs that block dopamine receptor sites are dopamine antagonist (antidopaminergic). Dopamine antagonists are a type of drugs which blocks dopamine receptors by receptor antagonism. Those antagonists are used as antipsychotics, so they have found use in treating schizophrenia, bipolar disorder, and stimulant psychosis. Also, they can be antiemetics used in the treatment of nausea and vomiting or used as <span>anti-depressants.</span></span>