After Enjoying a Perfectly Delicious Meal,Duane Treats Himself and Orders

After enjoying a perfectly delicious meal,Duane treats himself and orders a very expensive dessert.After one bite,Duane realizes he does not care for it at all.He chokes it down while thinking about the money he just wasted on it.Duane's decision to eat the entire dessert is an example of:

A) irrational behavior.
B) a cognitive bias,because he is focused on the money spent on the dessert.
C) considering a sunk cost instead of weighing marginal costs and benefits.
D) Duane's behavior exemplifies all of these.