An 18-year-old woman comes to the emergency room with recurrent facial edema, especially around her lips. She also has recurrent bouts of intense abdominal pain and cramps, sometimes associated with vomiting. Laboratory examination reveals decreased C4, while levels of C3, decay-accelerating factor, and IgE are within normal limits. A deficiency of which of the following substances is most likely to be associated with these findings?
This  women is suffering from hereditary angioedema.
C1 inhibitor blocks the activation of C1, the first protein of the classical complement pathway. Inherited deficiency of this inhibitor is the cause of hereditary angioedema.
Deficiency of decay accelerating factor (DAF), which breaks down the C3 convertase complex, is seen in paroxysmal nocturnal hemoglobinuria (PNH).
Reference-Robbins BASIC PATHOLOGY 10th edition pg- 77
C1 esterase inhibitor
Complement components C3 and C5
Decay-accelerating factor
None of the above