You are answering a USMLE-style medical question. Question: A 45-year-old man presents to the physician with complaints of increased urinary frequency and decreasing volumes for the past 2 months. He does not complain of any pain during urination. He is frustrated that he has to wake up 2 or 3 times per night to urinate even though he tried reducing the amount of water he consumes before bed and made some other dietary changes without any improvement. He has no family history of prostate disease. Physical examination is negative for any suprapubic mass or tenderness, and there is no costovertebral angle tenderness. Which of the following is the best next step in the management of this patient? Options: A) Urinalysis and serum creatinine B) Reassurance C) Digital rectal examination D) Prostate-specific antigen Reply with ONLY the letter of the correct answer (A, B, C, or D). No explanation.