Answer : The correct option is, (B) bonding and unshared pairs around central atom.
Explanation :
Lewis-dot structure : It shows the bonding between the atoms of a molecule.
When we are determining the shape of a molecule then it is important to draw a Lewis-dot structure and for drawing a Lewis-dot structure we should know that how many total number of valance electrons present in a given compound or a molecule.
For example:
The given molecule is,
![H_2CO_3](https://img.qammunity.org/2020/formulas/chemistry/middle-school/tq1qa417autuxyahr2rvk521doxdnk4iru.png)
As we know that hydrogen has '1' valence electrons, carbon has '4' valance electrons and oxygen has '6' valence electron.
Therefore, the total number of valence electrons in
= 2 + 4 + 18 = 24
Now we have to determine the hybridization of carbon in
![H_2CO_3](https://img.qammunity.org/2020/formulas/chemistry/middle-school/tq1qa417autuxyahr2rvk521doxdnk4iru.png)
Number of bond pairs = 3
Number of lone pairs = 0
Number of atomic orbitals around carbon atom = 3 + 0 = 3
So, hybridization will be
and the shape is, trigonal planar.
Hence, it is important to draw a Lewis Dot structure first in order to see the total number of bonding and unshared pairs around central atom.