Answer: Option 'C' is correct.
Explanation:
Since we have given that
Cost for 5 weeks i.e. 15 classes = $108
Cost of per class is given by

Cost for 8 weeks i.e. 24 classes = $125
Cost of per class is given by

Amount of saving of per class by taking the 8 week class is given by

Hence, Option 'C' is correct.