This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Pharmacology
[{'content': 'Denosumab, a monoclonal antibody against RANK ligand is used for the treatment of : \nSelect and explain. \nA. Rheumatoid arthritis, B. Osteoporosis, C. Osteoarthritis, D. Systemic lupus erythematosis', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Receptor for activated nuclear factor KB (RANK) is present on osteoclast progenitors. Binding of RANK-ligand to these receptors causes differentiation and activation of osteoclast progenitors to mature osteoclasts. Denosumab is a monoclonal antibody that prevents the binding of RANK-ligand with RANK. This prevents activation of osteoclasts and it can, therefore, be used in osteoporosis.\nOsteoblasts synthesize and release osteoprotegerin (OPG), identical with RANK, which functions as a decoy receptor. OPG thus inhibits the binding to RANK-L to RANK. Hence OPG analogs can be the potential therapeutic agents of osteoporosis.', 'role': 'assistant'}]