The question asks for the best and poorest conductors of heat. A good conductor of heat is a material that allows heat to flow easily through it, while a poor conductor, or insulator, does not allow heat to flow readily.

Option 1 states that silver (Ag) is the best conductor of heat, while lead (Pb) is the poorest conductor. Silver is indeed known for its high thermal conductivity, making it an excellent conductor of heat. On the other hand, lead is a relatively poor conductor of heat compared to other metals.

Option 2 suggests that copper (Cu) is the best conductor of heat, while aluminum (Al) is the poorest conductor. Copper is also known to have high thermal conductivity, making it an excellent conductor. Aluminum, although it has a relatively lower thermal conductivity compared to copper and silver, is still a reasonably good conductor of heat. Therefore, option 2 does not accurately represent the best and poorest conductors of heat.

Option 3 states that silver (Ag) is the best conductor of heat, while gold (Au) is the poorest conductor. While silver is indeed an excellent conductor of heat, gold is also a good conductor, although it has a lower thermal conductivity compared to silver. Therefore, option 3 is