On Admission, a Physician Diagnoses a Patient with Rheumatoid Arthritis

On admission, a physician diagnoses a patient with rheumatoid arthritis. The nurse uses assessments to make the nursing diagnosis of Chronic Pain. What is the nurse diagnosing?

A) the pathology of the illness
B) the response of the patient to the illness
C) information from a nursing textbook
D) knowledge from more experienced nurses