Two insulating materials of thermal conductivity K and 2K are available forlagging a pipe carrying a hot fluid. If the radial thickness of each material is the same _____.

A

Material with higher thermal conductivity should be used for the inner layer and one with layer and one with lower thermal conductivity for the outer

B

Material with lower thermal conductivity should be used for the inner layer and one with higher thermal conductivity for the outer

C

It is immaterial in which sequence the insulating materials are used

D

None of these