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
Recurrent gross hematuria is seen in - 
Select and explain. 
A. Alpo's syndrome, B. IgA nephropathy, C. Focal seg.GN, D. DM
B: IgA nephropathy
Answer: B: IgA nephropathy 
Explanation: The two most common presentations of IgA nephropathy are recurrent episodes of macroscopic hematuria during or immediately following an upper respiratory infection often accompanied by proteinuria or persistent asymptomatic microscopic hematuria. Ref:Harrison 20th edition pg no 2140