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 20 year old woman presents with bilateral conductive deafness, palpable purpura on the legs and hemoptysis. Radiograph of the chest shows a thin-walled cavity in left lower zone. Investigation reveal total leukocyte count 12000/mm3, red cell casts in the urine and serum creatinine 3mg/dl.What is most probable diagnosis - 
Select and explain. 
A. Henoch-Schonlein purpura, B. Polyarteritis nodosa, C. Wegner's granulomatosis, D. Disseminated
C: Wegner's granulomatosis
Answer: C: Wegner's granulomatosis 
Explanation: None