On what factors does the resistance of a conductor depend?

(N/A) The resistance of a conductor depends upon the following factors:
$(a)$ Length of the conductor: Resistance is directly proportional to the length $(R \propto l)$.
$(b)$ Cross-sectional area of the conductor: Resistance is inversely proportional to the cross-sectional area $(R \propto 1/A)$.
$(c)$ Material of the conductor: Resistance depends on the nature of the material, represented by its resistivity $(\rho)$.
$(d)$ Temperature of the conductor: For most conductors, resistance increases with an increase in temperature.