Electronics Engineering Question:

When a small amount of Cu is added to a Ni conductor, then the?
a) Resistivity of Ni will decrease at all temperatures because Cu is better conductor than Ni
b) Residual resistivity of Ni at low temperatures will increase as Cu atoms acts as defect centers
c) Resistivity of Ni will increase at all temperatures as Cu destroys the periodicity of Ni and acts as defects
d) Resistivity of Ni remains unaltered as Cu atoms give the same numbers of free electrons as Ni atoms