Conley Products would like to offer a special product to its best customers. However, the firm wants to limit its maximum potential loss on this product to the firm's initial investment. The fixed costs are estimated at $$3,600,$ the depreciation expense is $$870,$ and the contribution margin per unit is $$6\mathrm{.}89.$ What is the minimum number of units the firm should pre$-$sell to ensure its potential loss does not exceed the desired level?

$396$ units

$191$ units

$126$ units

$522$ units

$649$ units