The answer is D. Choosing a protein supplement.
It is the only action that can be completed effectively and safely. Diagnosing a disease through internet resources can be dangerous and people misdiagnose themselves causing panic and worry. The best way to diagnose a health problem is to speak to your doctor. Choosing an antidepressant is something only a professional medical practitioner can do. You cannot treat an eating disorder online, an eating disorder is a mental health condition and needs the right kind of treatment through psychological and medical support.
Most teens resist using tobacco because they know that it is bad, and if they start they might not be able to stop.
This is not a total answer, it is just my best guess. I hope this helps. If you have any other questions on this or other questions just ask. I am here to help you. As needed.