A student is sitting in class, thinking about the things he could currently be doing instead which includes: Working at the supermarket for $15/hr; Working as a builders labourer for $12/hr; Playing computer games which he values at $5/hr. Trying to find a girlfriend at a music festival which he values at $5/hr; All of these activities are mutually exclusive so he can't do more than one at the same time. The opportunity cost of him being in class is: Select one: a. $37/hr b. $27/hr c. $15/hr d. $12/hr e. $5/hr