Which list correctly identifies each particle?

x represents an electron and y represents a proton and a neutron.

Explanation:

electrons are the smallest particle in an atom and protons and neutrons are a lot larger. thats why only protons and neutrons are weighed in atomic mass. electrons are too small to make a difference in the atom's weight.

They want you to pick choice-A , but the whole question is poor and misleading.

The picture sorta kinda roughly presents the concept of the difference in MASSES ... one proton or one neutron has as much mass as about 1,840 electrons.

But things get very complicated on the scale of atoms and their components, and there's actually no such simple concept as the physical SIZE of any of these particles.

If ya wanna be absolutely technically correct, the picture is absurd, and the question has no answer.