This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: ULTRASOUND, Subject name: Radiology
SIS stands for- 
Select and explain. 
A. Saline infused sonography, B. System induced safety, C. Saline infusion syndrome, D. Self inflicted stab
A: Saline infused sonography
Answer: A: Saline infused sonography 
Explanation: SIS stands for- Saline infused sonography. USG used to evaluate tubal patency.