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 female patient Chandani develops chest pain which is not associated with exercise and chest auscultation shows multiple non ejection clicks. The investigation which is used to diagnose the disease is - 
Select and explain. 
A. Echocardiography, B. Pyrophosphate scan, C. Thallium 201scan, D. ECG
A: Echocardiography
Answer: A: Echocardiography 
Explanation: None