A company is considering purchasing a machine that costs $$200000$ and is estimated to have no salvage value at the end of its $8-$year useful life. If the machine is purchased, annual revenues are expected to be $$50000$ and annual operating expenses exclusive of depreciation expense are expected to be $$28000.$ The straight$-$line method of depreciation would be used. The cash payback period on the machine is

$4\mathrm{.}5$ years.

$10\mathrm{.}1$ years.

$9\mathrm{.}1$ years.

$8\mathrm{.}0$ years.