Answer : The correct option is, (a) metal
Explanation :
Conductors : Conductors are those in which the electric current can flow easily.
Insulators : Insulators are those in which the electric current can not flow.
Most of metals are conductors. That means it a good conductor of heat and electricity.
The non-metals are insulators. That means it is a bad conductor of heat and electricity.
From the given options, metal conduct heat well. While the other options, plastic, wood and glass does not conduct heat well.
Hence, the material conducts heat well is, metal.
