Answer: option B.with “Inside the nucleus,” because the particle is a neutron.
Step-by-step explanation:
You have to complete this table:
mass | location | charge
1 ? Has no charge
The atom is constituted by 3 subatomic particles, namely electron, proton, and neutron.
Since the gold foil experiment performed by Geiger and Marsden (1909), who collaborated with Ernest Rutherford, it was stablished that the atom contains a dense positively charged nucleus, which has almost all the mass of the atom.
The positive charge comes from the subatomic particle named proton.
A few time later, a second subatomic particle inside the nucleus, was discovered. This particle has not charge and has almost the same mass than the proton. Because the absence of charge it was named neutron.
Hence, the relative masses of the protons and neutrons are 1 / 1. As said, both are in the nucleus, and while the proton has positive charge, the neutron has no charge. So, the table is completed with inside the nucleus, because the particle is a neutron:
mass | location | charge
1 inside the nucleus Has no charge