How many of the following statements violate the sunk cost principle? I. I bought my tennis racket online at $300, but I found its head was too heavy for me so I choose to put it up for sale. I will...

How many of the following statements violate the sunk cost principle?

I. I bought my tennis racket online at $300, but I found its head was too heavy for me so I choose to put it up for sale. I will not sell it for less than $300 because that would be a loss to me.

II. Despite waiting in line for 3 hours for the Black Friday shopping day, Mary decided to go back home before the store opened since she cannot bear the cold wind.

III. A manager should look at her employee's past performance reviews when deciding whether to grant him a promotion.

a. 0

b. 1

c. 2

d. 3