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: Dental
A patient presents with history of episodic painful edema of face and larynx. Which of the following is likely to be deficient – 
Select and explain. 
A. Complement C3, B. Complement C5, C. C1 Esterase Inhibitor, D. Properidin
C: C1 Esterase Inhibitor
Answer: C: C1 Esterase Inhibitor 
Explanation: Recurrent episodes of edema of face and larynx suggest the diagnosis of hereditory angioneurotic edema caused by deficiency of C1 esterase inhibitor.