Answer:
Particles of the cathode rays are fundamental to all matter.
Matter contains negative charge and by inference positive charge.
There are subatomic size particles in an atom.
Cathode rays have mass.
Explanation:
This means that the cathode rays which are travelling towards anode (positively charged) are negatively charged. Atom was considered to have subatomic particles.
C and D are correct.
This means that particles of cathode rays are fundamental to all the matter.
A is correct.
It means that the cahrged particle has mass too.
D is correct.