Watson Corporation has a weighted$-$average unit contribution margin of $$600$ for its two products, Evidence Tracers and Investigative Tracers. Expected sales for Watson are $20,000$ Evidence Tracers and $80,000$ Investigative Tracers. Fixed expenses are $$2,400,000.$

How many total units in total $($Evidence Tracers and Investigative Tracers$)$ would Watson sell at the break$-$even point?

$16,000$

$4,000$

$20,000$

$80\mathrm{.}000$

$$3\mathrm{.}200$