91Ó°ÊÓ

First, let's briefly review the four types of chemical bonds mentioned in the problem: (A) Metallic binding: Metallic bonds involve the sharing of free electrons among a lattice of metal atoms. They exhibit high electrical and thermal conductivity, and are also opaque to visible light. (B) Ionic binding: Ionic bonds are formed between atoms with opposite charges, where electrons are transferred from one atom to another. They have high melting and boiling points and generally have low electrical conductivity in the solid state, but become more conductive when dissolved in water or in a molten state. (C) Covalent binding: Covalent bonds are formed when atoms share electrons to fill their outer electron shells. Covalent compounds typically have lower melting and boiling points than ionic compounds, and can be transparent to visible light. In most cases, these compounds have low electrical conductivity. (D) Vander Waals binding: Vander Waals bonds are weak physical interactions between molecules or atoms that arise from instantaneous dipoles. They have low boiling and melting points and are not conductive.

The given solid has two properties: 1. It is transparent to visible light. 2. Its conductivity increases with temperature.

Now, let's go through each bonding type and see which can fulfill these properties: (A) Metallic binding: This option can be eliminated because metallic compounds are opaque to visible light. (B) Ionic binding: This option can be eliminated because, although the conductivity of ionic compounds can increase with temperature due to higher ion mobility, they are not transparent to visible light. (C) Covalent binding: This option is a possibility because it can allow transparency to visible light. In addition, the conductivity of some covalent compounds, specifically semiconductors, increases with temperature. (D) Vander Waals binding: This option can be eliminated because Vander Waals compounds are not conductive.

From our analysis, the given solid with properties of transparency to visible light and increasing conductivity with temperature is consistent with covalent binding. Therefore, the correct answer is: (C) Covalent binding