The correct option is D It is the sum of the Kinetic energy of all the nucleons in the nucleus. Z
I hope you remember how we started this concept of binding energy by telling you that it is the energy required to separate the constituent nucleons in a nucleus to a large distance.
If energy is required in separating the nucleons, then if we are bringing the same free nucleons together, then exactly the reverse process will happen, right. Same amount of energy will be released. So you get Binding energy there.
How we calculate this binding energy for a nucleus is by finding the difference between the total rest mass energy of all nucleons and the rest mass energy of the nucleus.
B=(Zmp+Nmn−M)c2
Here Z is the number of protons and N is the number of Neutrons.
M is the mass of the nucleus.