The hollow cylinder of length 3.14 with the inner and outer diameter 4mm and 8mm and the resistance given as x10⁻3 ohms. Also, resistivity is given.

a) 2.5 x 10⁻3 ohms
b) 5 x 10⁻3 ohms
c) 7.5 x 10⁻3 ohms
d) 10 x 10⁻3 ohms