This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Heart & Pericardium, Subject name: Surgery
During examination of a 49-year-old male schoolteacher who presents with a swelling in the neck, palpation by a bounding pulse. Which test would be most likely to establish a possible cause of the underlying condition? 
Select and explain. 
A. Funduscopic eye examination, B. Liver-spleen scan, C. Thyroid function studies, D. X-ray of the chest and cervical spine
C: Thyroid function studies
Answer: C: Thyroid function studies 
Explanation: The pulse is bounding when the pulse pressure is magnified because of a wide difference between the systolic and diastolic pressure. It may be due to aortic incompetence, PDA, or noncardiac causes that result in increase in cardiac output and decreased peripheral resistance (e.g., hyperthyroidism, peripheral AV fistula, or anemia).