This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Tuberculosis of Bone and Joints, Subject name: Orthopaedics
A 35-year-old lady with chronic backache. On X-ray she had a D12 collapse. But interveebral disc space is maintained. All are possible except: 
Select and explain. 
A. Multiple myeloma, B. Osteoporosis, C. Metastasis, D. Tuberculosis
D: Tuberculosis
Answer: D: Tuberculosis 
Explanation: Characteristic radiological feature of Pott's spine Obliteration of disk space with destruction of two adjacent veebrae. Osteoporosis: Cod fish appearance is seen in which the disc bulges into the nearby veebral bodies and the disc becomes biconvex. Multiple myeloma: Wedge collapse of the veebra is seen and most of the time involving more than one veebra, commonly in the thoracic spine. Metastasis: Well circumscribed. Can be sclerotic e.g prostrate ;osteolytic e.g. renal and thyroid or mixed e.g. breast and lung