Walter Rents Some Ice Time at the Local Hockey Rink

Walter rents some ice time at the local hockey rink for 2 hours.After skating for an hour,he finds himself cold,tired,and hungry.If Walter decides to skate around for the other hour before leaving,it is likely because he:

A) is ignoring the sunk cost of the rink time.
B) is focusing on the sunk cost of the rink time.
C) is weighing his opportunity costs of the second hour against the benefits of the second hour of skating.
D) None of these is true.