Answer: Option (b) is the correct answer.
Step-by-step explanation:
A covalent bond is formed by sharing of electrons between the combining atoms. When only one electron is shared between the combining atoms then it is known as a single covalent bond.
On the other hand, sharing of two electrons is known as double covalent bond.
Less energy is required to break a single covalent bond as compared to a double covalent bond, ionic and hydrogen bond.
An ionic bond is formed by transfer of electrons and it occurs between atoms with opposite charges. Therefore, it is a strong bond.
Whereas hydrogen atom attached to another compound will result in the formation of a hydrogen bond.
Thus, we can conclude that in single covalent bond the forces of molecular attraction is the weakest.