Suppose Kim, a rational decision maker, is considering going to see Zoe Boekbinder in concert. Suppose further that the price of a ticket is $$10$ and tickets are non$-$refundable$/$non$-$exchangeable. To attend the show, Kim would have to give up the chance to work two hours of overtime, for which she would have been paid a total of $$30($i$.$e$.,$ $$15$ per hour$).$ If Kim had purchased a ticket before making the choice between working or going to the concert, what was the sunk cost in making her choice?

Select one:

A$.$ $$0.$

B$.$ $$10.$

C$.$ $$20.$

D$.$ $$30$

E$.$ $$40$

ear my choice