A nurse in a provider's office is evaluating the effectiveness of alendronate for a client who has osteoporosis. Which of the following diagnostic results should the nurse review?

A. Dual-energy x-ray absorptiometry (Dexa scan): Dexa scans measure bone mineral density and are the standard tool for diagnosing osteoporosis and monitoring the effectiveness of treatments like alendronate. Changes in bone density over time indicate how well the medication is working. B. Urine specific gravity: This test evaluates kidney function and hydration status but does not provide information about bone density or the effectiveness of osteoporosis therapy. C. Lumbar puncture: A lumbar puncture assesses cerebrospinal fluid for neurological conditions. It has no role in evaluating osteoporosis treatment or bone health. D. Hemoglobin A1C (Hb A1C): HbA1C measures average blood glucose over several months, used in diabetes management. It does not reflect changes in bone density or the impact of alendronate therapy.