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
DiGeorge’s syndrome is characterized by a deficiency of _____. 
Select and explain. 
A. B lymphocytes, B. T lymphocytes, C. Both B and T lymphocytes, D. Antibodies
B: T lymphocytes
Answer: B: T lymphocytes 
Explanation: DiGeorge’s syndrome is characterized by a deficiency of T cells. It is caused by the failure of the third and fourth brachial pouches to develop normally, resulting in a lack of thymus and parathyroid development.