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
Adenosine deaminase deficiency is seen in the following disease 
Select and explain. 
A. Common variable immunodeficiency, B. Severe combined immunodeficiency, C. Chronic granulomatous disease, D. Nezelof syndrome
B: Severe combined immunodeficiency
Answer: B: Severe combined immunodeficiency 
Explanation: None