This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: JIPMER 2019, Subject name: Pathology
Acute graft-versus-host-disease (GVHD) commonly involves all of the following organs, except: 
Select and explain. 
A. Brain, B. Skin, C. Liver, D. Small & large intestines
A: Brain
Answer: A: Brain 
Explanation: Graft-versus-host disease (GVHD) Occurs when immunologically competent cells or their precursors are transplanted into immunologically compromised recipients, and the transferred cells recognize alloantigens in the host and attack host tissues Most commonly seen in the setting of HSC transplantation Acute GVHD occurs within days to weeks after allogeneic HSC transplantation. Major clinical manifestations result from involvement of the immune system and epithelia of the skin, liver, and intestines. Generalised skin rash Destruction of small bile ducts gives rise to jaundice Mucosal ulceration of the gut gives rise to diarrhea