All of the following play a significant role in bone resorption except:: (A) Parathyroid hormone., (B) Interleukin1., (C) Interleukin6., (D) Interferon-gamma.
Answer is D. Pro-resorptive factors are hormones and cytokines are:-

PTH (Parathyroid hormone)
1,25dihydroxyvitamin D3,
IL-1
IL-6
TNF (Tumour necrosis factor)
LIF (Leukaemia inhibitory factor)
Corticosteroids, which activate osteoblasts and stroma cells to produce RANKL and depress OPG.