A 60-year-old woman with a 25-year history of type 2 diabetes mellitus presents with pruritus, diffuse bone pain, and proximal muscle weakness. Laboratory studies show a serum calcium level of 6.5 mg/dL, serum phosphate of 6.0 mg/dL, serum creatinine of 2.7 mg/dL, and intact parathyroid hormone of 300 pg/mL (normal: 10-65 pg/mL). The laboratory findings in this patient are most likely due to which of the following conditions?
(A) Parathyroid adenoma
(B) Parathyroid insufficiency
© Renal failure
(D) Underlying malignancy
(E) Vitamin D intoxication
Ans: © Renal failure