Option 1 states that the order of thermal conductivity is Copper < Aluminium < Stainless Steel. This means that copper has the lowest thermal conductivity, followed by aluminium, and then stainless steel. However, the correct order is Stainless Steel < Aluminium < Copper.
Option 2 states the correct order of thermal conductivity. It states that stainless steel has the lowest thermal conductivity, followed by aluminium, and then copper. This means that stainless steel is the least efficient in conducting heat, while copper is the most efficient.
Option 3 states that the order of thermal conductivity is Aluminium < Copper < Stainless Steel. This is the reverse of the correct order.
Option 4 states that the order of thermal conductivity is Copper < Stainless Steel < Aluminium. This order is also incorrect.
Therefore, option 2 is the correct answer as it accurately represents the order of thermal conductivity for aluminium, copper, and stainless steel.