Option A. This solid is ductile and conducts electricity.
Answer:  <u><em>Metallic solids</em></u>
Metallic solids have high melting point and also are good conductor of electricity and heat. Metallic solids are structured by metal atoms closely attached due to metallic bond. Example: Iron, copper & aluminum.
There are many forms of metals:
- Malleable : They can be molded into materials like sheets i.e by hammering . They can be pressed into shape without being smashed or cracked
 - Ductile:  They can be shaped into wires.
 - Solid: Most of the metals are solid are room temperature except mercury( which is a liquid). 
 
Metallic solids are ductile and conducts electricity. 
Option B. This solid is not conductive and has a low melting point.
Answer:  <em><u>Molecular solid</u></em> 
Molecular solids are consist of atoms or molecules. Molecular solids are not conductive and  have low melting point. Example: sucrose 
Reason behind not choosing other options: 
Iconic solids: Consists of positive and negative icons. Iconic bonds have high melting point and are poor conductors. They are very brittle and hard in form Example: NaCl
Network solids: Consists of atoms connected by covalent bonds. Network solids have high melting point and non/poor conductors. Example: diamonds