If a Copper wire of commercial purity is to conduct $5$ of current with maximum

voltage drop of $0\mathrm{.}4\frac{V}{m}.$ What must be its minimum diameter?

A$.4\mathrm{.}215{10}^{-4}m$

B$.2\mathrm{.}215{10}^{-4}m$

C$.1\mathrm{.}215{10}^{-4}m$

D$.5\mathrm{.}215{10}^{-4}m$

E$.3\mathrm{.}215{10}^{-4}m$