Fullerton, a merchandiser $($i$.$e$.,$ a trading company$),$ provided the following data $($all in $ except number of units information$)$:

$\backslash$table$[[,$Per Unit,Total$],[$Number of units sold,,$20,000],[$Selling price per unit,$30\mathrm{.}00,],[$Variable selling,$4\mathrm{.}00,],[$Variable admin,$2\mathrm{.}00,],[$Fixed selling exp,,$40,000],[$Fixed admin,$30,000,],[$Beginning merchandise inventory,$24,000,],[$Ending merchandise inventory,$44,000,],[$Merchandise purchase,$180,000,]]$

If the sales quantity is increased by $1,000$ units, what will be the incremental net operating income?

A$.16,000$

B$.30,000$

C$.24,000$

D$.22,000$

$[$Source: Brewer $9$ed$,$ Exercise $1-6.$modified$]$