Which particles have approximately the same mass?

(1) alpha particle and beta particle

(2) alpha particle and proton

(3) neutron and positron

(4) neutron and proton

The answer is (4) neutron and proton. The electron has very little mass and the neutron and proton have approximately the same mass. The positron has approximately the same mass as electron. The beta particle is electron. And the alpha particle is the nucleus of He which is about the same mass as 4 protons.