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: Radiology
Most important investigation for pericardial effusion – 
Select and explain. 
A. Cardiac catheterization, B. USG, C. Echocardiography, D. X-ray chest
C: Echocardiography
Answer: C: Echocardiography 
Explanation: 2 D-echo is the investigation of choice for pericardial effusion.