Answer: Option (b) is the correct answer.
Step-by-step explanation:
Insulator are the substances which do not conduct electricity. It is known that metals are good conductors of electricity. Whereas non-metals do not conduct electricity.
Out of the given options, silver, and calcium is a metal that means they are good conductors of electricity and are not insulators.
On the other hand, silicon is a metalloid, that is, it shows properties of both metals and non-metals. Hence, it will also show conductivity.
Phosphorus is a non-metal and therefore, it does not conduct electricity. As a result, out f the given options it will act as the best insulator.