A solid substance 'A' is very hard and electrical insulator both in the solid state as well as in molten state. It has also very high melting point. Is the solid metal like silver or network solid like silicon carbide (SiC) ?

Explanation

Since the solid begaves as an insulator even in the molten state, it cannot be a metal like silver. Therefore, it is a covalent or network solid like SiC.