How is the mass number calculated for an atom involved in nuclear fusion?(1 point)

Responses

It is the number of protons plus neutrons.
It is the number of protons plus neutrons.

It is the number of neutrons.
It is the number of neutrons.

It is the number of protons plus electrons.
It is the number of protons plus electrons.

It is the number of electrons.
It is the number of electrons.

It is the number of protons plus neutrons.