This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Immunology, Subject name: Microbiology
Deficiency of C1 inhibitor can produce 
Select and explain. 
A. Hereditary angioneurotic edema, B. SLE, C. No disease, D. Pyogenic infections
A: Hereditary angioneurotic edema
Answer: A: Hereditary angioneurotic edema 
Explanation: C3 def can lead to recurrent pyogenic infections C1 inhibitor deficiency can lead to hereditary angioneurotic edema Ref: Textbook of Microbiology Baveja 5th ed Pg 125