Answer:
b. The money a student spends on rent for his apartment while attending school.
Step-by-step explanation:
An opportunity cost is defined as the benefit forgone for choosing the current opportunity, as in the given case, anything which a student could do defines the opportunity cost, in case he did not go to school.
Here, statements a, c, and d clearly represents the opportunities forgone in choosing to attend the school by the student.
Statement b provides only the cost he incurs for current choice of going to school.
Therefore, Statement b is not an example of opportunity cost.