Dalton's atomic theory said, apart from other things, said that an atom was the smallest things and that all matter was composed of atoms.
But J. J. Thomson discovered the electrons, particles smaller than atoms, and after that, changes to Dalton's theory were made.
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Endocrine glands are responsible for <span>regulating body activities. The correct option among all the options that are given in the question is the second option or option "B". The endocrine system basically acts as long distance signalling system for the body. I hope that the answer has helped you.</span>