Scenario 18-2 George Has Two Jobs, One for the Winter and One

Scenario 18-2
George has two jobs, one for the winter and one for the summer.In the winter, he works as a lift operator at a ski resort where he earns $15 per hour.During the summer, George drives a tour bus from the resort to a nearby town and back several times a day, earning $18 per hour.
-Refer to Scenario 18-2.During the summer months,what is George's opportunity cost of taking an hour off work to go hiking

A) less than $15
B) $15
C) between $15 and $18
D) $18