37. According to the passage, which of the following is true?
(A) Too many free, unsupervised activities make it hard for teenagers to focus and sleep.
(B) A lack of guidance from parents is a main reason causing teenagers' mental health issues.
(C) Growing up in a phone-based childhood helps teenagers develop new skills and make friends easily.
(D) The loss of outdoor play in childhood and too much online time may cause teenagers' anxiety problems.