Name the region of the atom where protons and
neutrons are located. this region is indicated by
label b.
name the region of the atom where electrons are
located. this region is indicated by label a.
done

Answer : The subatomic particle protons (P) and neutrons (N) are located inside the nucleus and the subatomic particle electrons (E) is located around nucleus.

Explanation :

As we know that an atom is the smallest unit of a matter that consist of three subatomic particles which are electrons, protons and neutrons.

The protons and the neutrons are located inside the nucleus or center of the nucleus where the mass of the an atom is concentrated and the electrons are located around the nucleus.

The protons are positively charged, the electrons are negatively charged and the neutrons are neutral that means it has no charge.

In the given diagram, the subatomic particle protons (P) and neutrons (N) are located inside the nucleus and the subatomic particle electrons (E) is located around nucleus.

a corroding iron, if that's one of your choices