The Thermal conductivity of rod depends on the material of the rod. Heat transfer is due to free electrons and conductors like metals have electrons in their outer shell so as to move freely along the road. If the rod is made up of non-conducting material then the transfer of heat would not pe possible as they don’t have free electrons .
Thermal conductivity does not depend on mass as the mass of the rod remains the same and it doesn’t affect the number of free electrons in the rod.
Thermal conductivity does not depend on length and area of cross section as thermal conductivity is the ability of a material to conduct heat and the dimensions of the material does not affect its ability.
Thus, option (d) is the correct option.