A 68-year-old man with a 3-year history of lower urinary tract symptoms (LUTS) presents with nocturia (×4 per night), weak urinary stream, and incomplete emptying. His IPSS score is 22. Digital rectal examination reveals a smooth, firm, symmetrically enlarged prostate. Post-void residual (PVR) is 80 mL. Serum PSA is 2.8 ng/mL. He has not received any prior treatment. What is the most appropriate next step in management?