Which of these is not an example of a sunk cost that is subject to poor economic decision making?

Which of these is not an example of a sunk cost that is subject to poor economic decision making?

Question 2 options:

a) 

a registration fee for a local 10K race

b) 

an appraisal fee to determine the value of a house you are thinking of buying

c) 

tuition that you paid for an economics course

d) 

a new laptop that you purchased for school