This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: G.I.T, Subject name: Surgery
Initial investigation of choice in obstructive jaundice is 
Select and explain. 
A. USG, B. ERCP, C. CT scan, D. PTC
A: USG
Answer: A: USG 
Explanation: Transabdominal ultrasound scan is universally established as the most useful first line imaging study in the jaundiced adult.It provides an excellent evaluation of liver parenchyma & assessment of the presence/absence of bile duct dilatation. Reference:SRB's manual of surgery,5th edition,page no:656.