Which Statement Is False Concerning the Skeletal Alterations Caused by Chronic

Which statement is false concerning the skeletal alterations caused by chronic renal failure when the glomerular filtration rate (GFR) declines to 25% of normal?

A) Parathyroid hormone is no longer effective in maintaining serum phosphate levels.
B) The parathyroid gland is no longer able to secrete sufficient parathyroid hormone.
C) The synthesis of 1,25-vitamin D3, which reduces intestinal absorption of calcium, is impaired.
D) The synthesis of 1,25-vitamin D3, which impairs the effectiveness of calcium and phosphate resorption from bone by parathyroid hormone, is impaired.