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.
