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 28-year-old male, who was known case of mitral valvular heart disease developed weakness on the right side of the body which gradually recovered completely over a period of 2 weeks. Blood pressure of the patient was normal and laboratory studies did not reveal any significant abnormality. What is the diagnosis? 
Select and explain. 
A. TIA, B. Ischemic stroke, C. Hemorrhagic stroke, D. Cerebral salt wasting syndrome
B: Ischemic stroke
Answer: B: Ischemic stroke 
Explanation: None