Osteoclast are stimulated by: (A) Thyroxine, (B) PTH, (C) Calcitonin, (D) Estrogen
Answer is B. Refer Robbins page no 1207-1208 Parathyroid hormone related protein (PTHrP) is a local factor, expressed by perichondrial stromal cells and early proliferating chondrocytes, that activates the PTH receptor and maintains proliferation of chondrocytes.