Answer: Option (a) is the correct answer.
Step-by-step explanation:
Ionic compounds have atoms bonded through ionic bonds.
An ionic bond is formed when there is transfer of electrons from one atom to another. Also, ionic compounds have opposite charge on their atoms hence, they are attracted by strong intermolecular forces.
Thus, compound whose atoms are holded by strong intermolecular forces of attraction are solid.
Therefore, we can conclude that ionic compounds are normally in solid physical state at room temperature.