The Lewis dot structures can be written by adopting the following steps : I. The total number of electrons required for writing the structure are obtained by adding the valence electrons of the combining atoms. II. Knowing the chemical symbols of the combining atoms and having knowledge of the skeletal structure of the compound, it is easy to distribute the total number of electrons as bonding shared pairs between the atoms in proportions to the total bonds. III. In general the least electropositive atom occupies the central position in the molecule/ion. IV. After accounting for the shared pairs of electrons for single bonds, the remaining electron pairs are either utilized for multiple bonding or remain as the lone pairs. Which of the above step(s) is/are incorrect? Choose the correct option.