Reason; The SI units of resistivity are ohm metre (Ωm) and ohm centimeter (Ωm)
Assertion The resistivity for a substance is its resistance when its is one meter line and its area of cross section is one square meter.

A. Both Assertion and Reason are correct and Reason is the correct explanation for Assertion
B. Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion
C. Assertion is correct but Reason is incorrect
D. Both Assertion and Reason are incorrect