This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Kidney, Subject name: Medicine
RBC casts are found in - 
Select and explain. 
A. DM, B. Wegeners Granulomatosis, C. SEE, D. Ankylosing spondylitis
B: Wegeners Granulomatosis
Answer: B: Wegeners Granulomatosis 
Explanation: One of the component of Wegener's granulomatosis is focal or diffuse necrotising glomerulonephritis , which is the reason for the presence of RBC casts. Ref Harrison20th edition pg 2122