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: Surgery
A 55-year-old male patient underwent cholecystectomy for Gall stone calculus. During surgery the patient's pulse was irregulary irregular, 160/min, BP = 80/50 mm of Hg, temp. 40degc On examination a swelling in the neck was found. Most likely diagnosis is - 
Select and explain. 
A. Thyroid storm, B. Myocardial infarction, C. Arhmias, D. Stridor
A: Thyroid storm
Answer: A: Thyroid storm 
Explanation: Ans. is 'a' i.e., Thyroid Storm