Elsa purchased concert tickets about two months ago. Today is the concert but it's raining out, meaning Elsa would have to purchase an umbrella and rain boots if she still wants to go. Why is Elsa still likely to be persuaded to attend the concert? a. social proofb. reactancec. reciprocityd. sunk costs

Option (d) is correct.

Explanation:

Sunk costs are the costs that are already occured in the past and cannot be recovered by the firms.

In this case, sunk costs are referred as the price of the concert tickets, whose cost cannot be recovered by the Elsa and this cost is incurred two months ago. That's Elsa wants to attend the concert despite raining.