This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Immunology Pa 3 (Graft, Autoimmunity, Immunodeficiency Disorders), Subject name: Microbiology
Chediak higashi syndrome, defect is- 
Select and explain. 
A. Fusion of lysosome, B. T-cells, C. B-cells, D. Complement
A: Fusion of lysosome
Answer: A: Fusion of lysosome 
Explanation: Chediak higashi syndrome -Defective phagolysosomal fusion leading to decrease in melanocytes Severe Combined Immunodeficiency- Deficiency of Purine Nucleoside Phosphorylase Chronic Mucocutaneous Candidiasis- T cell disorder leading to recurrent candidiasis X linked Hyper IgM Syndrome- Deficiency of CD40 Ligand on activated T cell