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: Pathology
Primary antibody deficiencies are characterized by 
Select and explain. 
A. Recurrent allergic reactions, B. Recurrent bacterial infections, C. Implicit allergic reactions, D. Implicit bacterial infections
B: Recurrent bacterial infections
Answer: B: Recurrent bacterial infections 
Explanation: None