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: Medicine
A 60 year old man with progressive dementia of recent onset presents with intermittent irregular jerky movemets. EEG shows periodic sharp biphasic waves. The most likely diagnosis is - 
Select and explain. 
A. Alzheimers's disease, B. Creutzfeldt Jakob disease, C. Lewy body dementia, D. Herpes simplex Encephalitis
B: Creutzfeldt Jakob disease
Answer: B: Creutzfeldt Jakob disease 
Explanation: None