Final answer:
About 20% of children have experienced a seriously debilitating mental disorder at some point, indicating the need for early mental health recognition and intervention. Therefore, the correct option is C.
Step-by-step explanation:
According to the National Institute of Mental Health (NIMH), approximately 20% of children, currently or at some point during their life, have had a seriously debilitating mental disorder. This data highlights the prevalence of mental health issues among the younger population and underscores the importance of recognizing and addressing mental health from an early age. Serious mental illnesses can significantly impact daily living and may include disorders such as anxiety disorders, major depression, bipolar disorder, and others.