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: Medicine
A 58 years old woman, who had backache and recurrent chest infections for 6 months, develops sudden weakness of the legs and urinary retention. His investigations show a hemoglobin of 7.3 gm/dl, serum calcium 12.6 mg/dl, phosphate-2.5 mg/dl, alkaline phosphatase-100 u/1, serum albumin-3 gm/dl, globulin-7.1 gm/dl and urea-178 mg/d. What is the most likely diagnosis? 
Select and explain. 
A. Lung cancer, B. Disseminated tuberculosis, C. Multiple myeloma, D. Osteoporosis
C: Multiple myeloma
Answer: C: Multiple myeloma 
Explanation: The above mentioned features are consistent with the diagnosis of mutiple myeloma. So multiple myeloma is the single best answer of choice. Ref: Harrison's Principles of Internal Medicine, 16th Edition Pages 657-60; Ferri's Clinical Advicer, 2009, Page 589.