The correct answer is D.
Aluminium has a higher specific volume than copper. This means that a given mass of aluminium will have a larger volume than the same mass of copper. This is because aluminium has a lower density than copper.
Aluminium also has a higher electrical conductivity than copper. This means that aluminium is a better conductor of electricity than copper. This is because aluminium has a higher number of free electrons than copper.
Aluminium also has a higher coefficient of linear expansion than copper. This means that aluminium will expand more than copper when heated. This is because aluminium has a higher atomic radius than copper.
However, aluminium has a lower resistance per unit length for the same cross-section than copper. This means that a given length of aluminium wire will have a higher resistance than the same length of copper wire. This is because aluminium has a higher resistivity than copper.
The resistivity of a material is a measure of how difficult it is for electricity to flow through the material. The resistivity of aluminium is about 2.65 times higher than the resistivity of copper. This means that aluminium is a poorer conductor of electricity than copper.
The reason for the higher resistivity of aluminium is that aluminium has a higher number of defects in its crystal structure than copper. These defects act as obstacles to the flow of electrons, and this increases the resistance of the material.