This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Bacteriology, Subject name: Microbiology
Most common genetic factor in Neisseria infection is 
Select and explain. 
A. Male gender, B. HLA b27, C. Complement deficiency, D. IgG deficiency
C: Complement deficiency
Answer: C: Complement deficiency 
Explanation: Complement deficiencies are said to comprise between 1 and 10% of all primary immunodeficiencies. The genetic deficiency of early components of the classical pathway (C1q, C1r/s, C2, C4) tends to be linked with autoimmune diseases, whereas C5 to C9 deficiency may have enhanced susceptibility to meningococcal disease. Reference: Textbook of Microbiology; Anathanarayan and panicker's; 10th edition; Pg: 232