A wire of 50 cm long and 1 mm2 in cross-sectional area carries a current 4A when connected to a 2V battery. The resistivity of the wire is

• A. 4 x 10-6 Ωm
• B. 2 x 10-7 Ωm
• C. 5 x 10-7 Ωm
• D. 1 x 10-6 Ωm