A copy editor can proof read a single manuscript in $30$ minutes. Over the course of a year, the copy editor proof reads all the manuscripts for $10$ research journals. Each research journals publishes $4$ issues per year and there are an average of $6$ manuscripts in each issue. If the copy editor is paid $$30$ an hour, how much is the copy editor's annual proof reading labor cost to the university?

$$7,200$

$$2,400$

$$3,600$

$$18,000$