a. The resistivity of the copper is 1.68 × 10‌–8 b. The resistivity of the manganin is 4.82 × 10‌–7 c. The resistivity of the aluminium is 2.65 × 10‌–8 d. The resistivity of the iron is 9.71 × 10‌–8 So copper has the least resistivity than iron, manganin and aluminium.