A nichrome wire $50\; cm$ long and $1 \; mm^2$ cross-section carries a current of $4\;A$. When connected to $2$ volt battery. The resistivity of nichrome with in $\Omega^{-m}$ is :

Question

( A ) $4 \times 10^{-7}$
( B ) $2 \times 10^{-7}$
( C ) $3 \times 10^{-7}$
( D ) $1 \times 10^{-6}$