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
Which of the following statements about Wilson's disease is TRUE? 
Select and explain. 
A. Low serum ceruloplasmin and low urinary copper, B. Low serum ceruloplasmin and high urinary copper, C. High serum ceruloplasmin and low urinary copper, D. High serum ceruloplasmin and high urinary copper
B: Low serum ceruloplasmin and high urinary copper
Answer: B: Low serum ceruloplasmin and high urinary copper 
Explanation: In Wilsons disease, due to deficiency of ATP7B protein, biliary copper excretion is impaired and it accumulates in the liver. Defective copper incorporation into ceruloplasmin leads to its excess catabolism and lower ceruloplasmin levels. Serum copper levels are usually lower than normal because of low blood ceruloplasmin. As the disease progresses, free copper levels increase and is deposited in various organs and is excreted in the urine. Ref: Harrison's principles of internal medicine 18th edition/ chapter 360.