When a charged particle moves through a magnetic field, it experiences a force known as the magnetic force. The magnitude of the magnetic force on a charged particle is given by the equation F = qvBsin[REPLACEMENT], where q is the magnitude of the charge, v is the velocity of the particle, B is the magnitude of the magnetic field, and [REPLACEMENT] is the angle between the velocity vector and the magnetic field vector.

In this case, the proton and the electron have equal velocity, so v is the same for both particles. Additionally, they are both passing through the same uniform magnetic field, so B is also the same. Since the charge of a proton is opposite to the charge of an electron, q is different for the two particles.

Given that the velocity and magnetic field are equal for the proton and the electron, the only differing factor is the charge. Therefore, according to the equation F = qvBsin[REPLACEMENT], the force experienced by the proton and the electron is proportional to their respective charges.

Hence, option 1 is correct because the proton and the electron experience equal and opposite forces due to their opposite charges.