Answer:
a. Out-of-pocket costs
c. opportunity costs
Explanation:
Out of pocket costs are those that have to be incurred by the student for having to take the additional classes if there are any. This needs to be considered as they are a cost that the student will need to pay for to take the classes and therefore might need budgeting.
Opportunity costs are the returns offered by the next best alternative to the current decision being taken. In other words, the student needs to consider what will happen if they pick additional class over work and vice versa.