Answer:
B. Metallic
Explanation:
It is the metallic ions that offer resistance to the electron flow.
Resistance in a circuit is due to the opposition to the flow of current (flow of electrons) . Resistance depends on the characteristics of the material, like resistivity , length and area of cross section of the metal.
If a material has more resistivity, resistance is more and vice versa. If the length is more or if the length is increased, keeping the area of cross section same, for a given material, the metallic ions colliding with the electrons have to travel a greater distance, there by increasing the resistance.
