Answer:
C. the longer you choose to study will result in an increase in the number and value of foregone activities.
Step-by-step explanation:
An opportunity cost refers to the loss of any potential gain by choosing or selecting an alternative from a list of other alternatives.
In the context, when preparing for a next day exam and by studying for a longer period of time increases the opportunity cost for the foregone activities.
Hence the correct option is (C).