Sunland Co$.$ is considering purchasing a new machine that will cost $$234600,$ but which will decrease costs each year by $$46000.$ The useful life of the machine is $10$ years. The machine would be depreciated straight$-$line with no residual value over its useful life at the rate of $$\frac{23460}{?}$ year. The payback period is

$5\mathrm{.}6$ years.

$5\mathrm{.}1$ years.

$6\mathrm{.}1$ years.

$10\mathrm{.}0$ years.