This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: C.N.S, Subject name: Medicine
Definition of TIA is, patient signs and symptoms resolve by 
Select and explain. 
A. 24 hours, B. 36 hours, C. 48 hours, D. 72 hours
A: 24 hours
Answer: A: 24 hours 
Explanation: When blood flow is quickly restored, brain tissue can recover fully and the patient's symptoms are only transient, this is called a transient ischemic attack (TIA). The definition of TIA requires that all neurologic signs and symptoms resolve within 24 h without evidence of brain infarction on brain imaging. Most TIAs last <1 h.Stroke has occurred if the neurologic signs and symptoms last for >24 h or brain infarction is demonstratedRef: Harrison 19e pg: 2559