This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: FMGE 2019, Subject name: Microbiology
Subacute Sclerosing Panencephalitis is a rare and dangerous complication of; 
Select and explain. 
A. Measles, B. Mumps, C. Rubella, D. Varicella
A: Measles
Answer: A: Measles 
Explanation: SSPE Subacute sclerosing Pan encephalitis (SSPE) is a rare complication of measles. SSPE occurs in about 1 in every 300,000 natural cases of measles. It is a form of chronic progressive brain inflammation caused by slow infection with ceain defective strains of hypermutated measles virus It is also known as Dawsondisease,Dawsonencephalitis, andmeaslesencephalitis