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: Orthopaedics
60 yrs old male with bony abnormality at upper tibia associated with sensorineural hearing loss. On laboratory examination serum alkaline phosphatase levels are (440mU/I) elevated and serum Ca ++ and PO4- are normal, Skeletal survey shows ivory vertebrae and cotton wool spots in x-ray skull.Diagnosis is - 
Select and explain. 
A. Fibrous dysplasia, B. Paget's disease, C. Osteosclerotic metastasis, D. Osteoporosis
B: Paget's disease
Answer: B: Paget's disease 
Explanation: Increased serum alkaline phosphatase
Normal calcium and phosphate
Bony lesions in skull and vertebrae
Sensorineural hearing loss


Amongst the given option, these feature can occur only in Paget's disease.