see I won't explain all the points but will tell you the concept being used.
protons and neutrons are inside the nucleus in an atom while the electrons are outside the nucleus.
the mass number of an atom is equal to the sum of number of electrons and neutrons in an atom
atomic number is equal to the number of electrons which is equal to the number of protons in an atom
no. of electrons/ protons is always less than that of neutrons and they're almost equal( a large difference ain't obtained between the number of electrons and that of neutrons.
since, the rest of the options are violating the above rules they're incorrect
