Answer: Option (B) is the correct answer.
Step-by-step explanation:
A conductor is defined as a substance that allows flow of electrons through it due to which there will be flow of electric current.
Whereas an insulator is defined as a substance through which there will be very less or no flow of electrons. As a result, there will be no flow of electric current through it.
Also, when a material is covalently bonded then it means sharing of electrons has taken place between its atoms. And, covalent materials do not allow flow of electric current through it because of no presence of free electrons or ions.
Thus, we can conclude that the statement it is an insulator best describes a covalently bonded material.