What is the maximum size copper bonding jumper for a metal water piping system installed for a building that is supplied by a $4,000$ ampere, $3-$phase, $4-$wire, $480\frac{Y}{277}-$volt service?

a$.6$ AWG copper or $4$ AWG aluminum or copperclad aluminum

b$.\frac{3}{0}$ AWG copper, $250$ kcmil aluminum or copp clad aluminum

c$.$ Not less than $12\mathrm{.}5\%$ of the largest ungrounde service conductor

d$.$ Not less than the size required by $250\mathrm{.}122$ us the rating of $4,000$A overcurrent protective devic