Read the passage below and answer the question.

Atom contains dense mass at its center, called nucleus. Nucleus is positively charged. Nucleus is made up of neutrons and protons. Therefore, it may be expected that the mass of the nucleus is equal to its individual protons and neutrons. However, the nuclear mass M is found to be always less than this. 

If m_n is the mass of neutron and m_p is the mass of proton, Z is the atomic number of the nuclei in question and M is the mass of the nucleus, then which of the these represents the mass defect?

[Zm_p + (A-Z)m_n] - M

Mass Defect : \(\Delta \)M = [Zm_p + (A-Z)m_n] - M