Answer: c. The $13,500 is taxable compensation.
Step-by-step explanation:
The $13,500 received is to be considered a taxable compensation because amounts paid for teaching or research, even to students, should be included in the gross income calculation which makes it a taxable compensation.
There are some exceptions to this however such as income from the National Health Service Corps Scholarship Program, the Armed Forces Health Professions Scholarship and Financial Assistance Program but this does not apply here.