Answer:
option a
Step-by-step explanation:
Process of hybridization is explained by valence bond theory.
According to valence bond theory, during the formation of a covalent bond, atomic orbitals of similar energy are combined to produce set of hybrid orbitals. These hybrid orbitals are of equal energy and overlap to form covalent bond.
So, valence bond theory describes covalent bond as a result of the overlap of hybrid orbitals
So, among the given option A is correct.