This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Haematology, Subject name: Medicine
True about smoldering myeloma is - 
Select and explain. 
A. Monoclonal gammopathy, B. Lytic bone lesion, C. Hypercalcemia, D. Bone marrow plasma cell > 10%
A: Monoclonal gammopathy
Answer: A: Monoclonal gammopathy 
Explanation: Smoldering multiple myeloma (SMM) is an early precursor to a rare blood cancer known as multiple myeloma, which affects plasma cells. This type of cancer produces ceain proteins that can be measured in both blood and urine. These proteins show up before a person has any symptoms of cancer. Ref Davidson 23rd edition pg 789