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 patient presents with melaena. normal renal function, hypertension and mononeuritis multiples. The most probable diagnosis is 
Select and explain. 
A. Classical polyarteritis nodosa, B. Microscopic polyangiitis, C. Henoch-Schonlein purpura, D. Buerger's disease
A: Classical polyarteritis nodosa
Answer: A: Classical polyarteritis nodosa 
Explanation: None