Particle(s) with zero charge:

Correct answer: b iii

The neutron has no charge; the electron is negative and the proton positive.

Why the other options are wrong

• a ii: ii is false: the proton's charge is +1.60 × 10⁻¹⁹ coulomb; only the neutron has zero charge.
• c i and ii: i and ii are both false: the electron is negative and the proton positive; only the neutron has zero charge.
• d ii and iii: ii is false: the proton's charge is +1.60 × 10⁻¹⁹ coulomb; only the neutron has zero charge.