The total number of electrons in an atom can be determined by looking at the electron configuration of the atom. The electron configuration describes how the electrons are distributed among the different energy levels or shells of an atom. In this case, we are given that the K, L, M, and N shells of the atom are full.

1. Understanding electron shells:
- Electrons are arranged in energy levels or shells around the nucleus of an atom.
- The first shell, known as the K shell, can hold a maximum of 2 electrons.
- The second shell, known as the L shell, can hold a maximum of 8 electrons.
- The third shell, known as the M shell, can also hold a maximum of 8 electrons.
- The fourth shell, known as the N shell, can hold a maximum of 18 electrons.

2. Determining the total number of electrons:
- Since the K, L, M, and N shells are full, we know that the maximum number of electrons in each shell has been reached.
- The K shell is full with 2 electrons, the L shell is full with 8 electrons, the M shell is full with 8 electrons, and the N shell is full with 18 electrons.
- To determine the total number of electrons, we simply add the number of electrons in each shell: 2 + 8 + 8 + 18 = 36.

3. Understanding the correct answer:
- The correct answer is given as option 'A' with a total of 60 electrons.
- However, based on the information provided, this answer is incorrect.
- The correct total number of electrons in the atom is 36, not 60.

In conclusion, the total number of electrons in the atom with full K, L, M, and N shells is 36, not 60 as stated in option 'A'.

The K shell is full with 2 electrons, the L shell is full with 8 electrons, the M shell is full with 8 electrons, and the N shell is full with 18 electrons. - To determine the total number of electrons, we simply add the number of electrons in each shell: 2 + 8 + 8 + 18 = 36.