-1 A 4m long wire of cross-sectional area 2.5 X 10 m² has a resistance of 5. The conductivity of the wire is (a) 2.5 X 10' m (b) 4.0 X 10' m (c) 2.5 X 10'' m¹ -1 -1 (d) 4.0 X 10''m'​