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
[{'content': 'Deficiency of C1 (complement 1) inhibitor results in - \nSelect and explain. \nA. SLE, B. Hereditary angioneurotic edema, C. Severe recurrent pyogenic infection, D. Gram-negative bacteremia', 'role': 'user'}, {'content': "Answer: B \nExplanation: The deficiency of C1 inhibitor is associated with hereditary angioneurotic edema. It is a condition characterized by episodic angioedema of the subcutaneous tissues or of the mucosa of the respiratory or alimentary tracts. Fatal if larynx or trachea affected. The attack is precipitated by local exhaustion of the reduced amount of the C1 inhibitor present, lea ding to the autocatalytic activation of C1 and unrestrained breakdown of C4 and C2. RefeReference:thanarayan & paniker's 9th edition, pg no: 126 <\\p>", 'role': 'assistant'}]