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
Preferred Investigation for diagnosing Acute Appendicitis in children? 
Select and explain. 
A. USG, B. CECT, C. MRI, D. X - Ray
A: USG
Answer: A: USG 
Explanation: *Graded compression Ultrasonography is the preferred initial imaging modality in the evaluation of Acute Appendicitis in children.