This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Symptoms and signs in psychiatry and classification, Subject name: Psychiatry
Fluctuating level of consciousness is seen in 
Select and explain. 
A. Hysteria, B. Delirium, C. Dementia, D. Mania
B: Delirium
Answer: B: Delirium 
Explanation: Delirium is characterized by an acute decline in both the level of consciousness and cognition with paicular impairment in attention. Reference: Kaplan & Sadock's Synopsis of Psychiatry: Behavioral Sciences/Clinical Psychiatry, 11th Edition, page 697.