Beta Blockers USMLE Step 1 Practice Question

A 55-year-old woman with a history of recurrent calcium oxalate kidney stones and mild hypertension is brought to her primary care physician for a routine follow-up visit. Her blood pressure today is 148/92 mmHg, heart rate is 78 bpm, and BMI is 27 kg/m². Three months ago, she was started on a once-daily oral antihypertensive diuretic to manage her blood pressure while potentially reducing urinary calcium excretion given her stone history. She reports no polyuria, polydipsia, muscle weakness, or flank pain. Repeat laboratory workup reveals serum calcium of 10.8 mg/dL, uric acid of 7.2 mg/dL, potassium of 3.3 mEq/L, and serum creatinine of 0.9 mg/dL. Her 24-hour urine collection demonstrates significantly decreased urinary calcium excretion compared to her baseline. Which diuretic class was most likely prescribed?