If a person has reached the age of 25 and not shown any signs of mental illness, can they assume that it will not be an issue for them? A. Yes, young people are most prone to mental illness. B. No, most mental illness emerges when people are senior citizens. C. No, mental illness can emerge later in life, particularly if there is trauma. D. Yes, even those with a family history of mental illness will show signs by 25.