A 55-year-old woman is evaluated for recurrent kidney stones, bone pain, and fatigue. Laboratory results show a serum calcium of 11.8 mg/dL (normal 8.5-10.2 mg/dL) and a serum phosphate of 2.1 mg/dL (normal 2.5-4.5 mg/dL). Which of the following is the most likely additional finding?

✓ Correct Answer: Option B

The patient's presentation with hypercalcemia, hypophosphatemia, kidney stones, and bone pain is classic for primary hyperparathyroidism. This condition is characterized by inappropriately elevated parathyroid hormone levels, which cause increased calcium reabsorption and phosphate excretion.