Final answer:
The most therapeutic response would be to conduct a thorough assessment and refer the student to a mental health professional for further evaluation and treatment.
Step-by-step explanation:
The most therapeutic response by the nurse to the 20-year-old student who is experiencing increasing anxiety, loss of appetite, and an inability to concentrate would be to conduct a thorough assessment and refer the student to a mental health professional for further evaluation and treatment.
The nurse can start by asking open-ended questions to gather more information about the student's symptoms, their duration, and any triggers or stressors that may be contributing to their mental health concerns. It is important for the nurse to provide emotional support, validate the student's feelings, and emphasize the importance of seeking appropriate help from a mental health professional.