A 68-year-old man presents to the clinic with progressive urinary hesitancy, weak stream, and nocturia over the past year. He denies dysuria, hematuria, or fever. Digital rectal examination reveals a smooth, symmetrically enlarged prostate without nodules. Post-void residual volume is mildly elevated. The patient is diagnosed with benign prostatic hyperplasia (BPH) and would like to start medical treatment. Which of the following is the preferred initial pharmacotherapy for most patients with symptomatic BPH?