Solid A is very hard, electrical insulator in solid as well as molten state and melts at extremely high temperature. What type of solid is it?

Solid A is very hard, electrical insulator in solid as well as molten

1.	Solid A is very hard, electrical insulator in solid as well as molten state and melts at extremely high temperature. What type of solid is it?
Answer» Solution :Covalent Network SOLID like `SiO_2` (QUARTZ) or SIC or C (diamond)