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.
The answer to ur question is a
Similar to those performed by the cell organelles in group b
Lavoisier would have taken mercury and heated it up to 350 degrees centigrade in air and then found that a new compound was formed a red or yellow mineral which would be mercury oxide so the experimental observation would be the change in color of the mercury and the formation of a mineral with different properties from pure mercury.
It’s B. “It was doubled...”
Hope this helps... ^^
