The question asks us to identify the baryons among the given options: electron, proton, and neutron.

To begin, let`s define what a baryon is. Baryons are subatomic particles that are made up of three quarks. They are a type of hadron, which are particles composed of quarks.

Analyzing each option:

- Option 1 states that only the electron is a baryon. However, this is incorrect because the electron is not composed of quarks. It is a type of elementary particle classified as a lepton.

- Option 2 suggests that both the proton and neutron are baryons. This is correct as both the proton and neutron consist of quarks and are examples of baryons.

- Option 3 claims that the neutron and electron are baryons. As previously mentioned, the electron is not a baryon, so this option is incorrect.

- Option 4 states that all three particles, electron, proton, and neutron, are baryons. However, the electron is not a baryon, so this option is also incorrect.

Therefore, the correct answer is option 2: the proton and neutron are the baryons among the given particles.