$($CH C$15)$ Steve files his return on April $1$ and pays the entire amourt of tax for the year at that time, $$5\mathrm{.}000.$ He is audited and pays the deficiency of $$1,500$ two years later. The maximum amount Steve may fle a daim for refund for eighteen months later is

$$6\mathrm{.}500.$

$$5,000.$

$$1,500.$

some other amount.