Final answer:
Medication is not the sole solution for all mental health issues.
Step-by-step explanation:
The misconception commonly held about mental illness is C) Medication is the sole solution for all mental health issues. While medication can be an important part of treatment for some individuals with mental illness, it is not the only solution. Mental health issues often require a multi-faceted approach, including therapy, lifestyle changes, and support systems. Medication is just one tool in the broader treatment plan.