Why did J. J. Thomson reason that electrons must be a part of the atoms of all elements?

Question

Why did J. J. Thomson reason that electrons must be a part of the atoms of all elements?

A Cathode rays are negatively-charged particles.

B Cathode rays can be deflected by magnets.

C An electron is 2000 times lighter than a hydrogen atom.

D Charge-to-mass ratio of electrons was the same, regardless of the gas used.

Answer 1

 its A dumbass