$3.$ Bob wishes to challenge a tax deficiency in the Court of Federal Claims. He must:

I. sue for a refund after awaiting the prescribed time

II$.$ file a claim for a refund with the IRS

III. wait six months, provided the Service has not denied the refund sooner

IV$.$ pay all taxes in question immediately

a$.$ I and IV only

b$.$ IV only

c$.$ II and III only

d$.$ I, II$,$ III, and IV