Which one of the following should be the minimum distance between two

Which one of the following should be the minimum distance between two items going through the X-BIS ?

20 cm
30 cm
60 cm
40 cm
This question was previously asked in
UPSC CISF-AC-EXE – 2020
The minimum distance between two items on the conveyor belt of an X-ray Baggage Inspection System (X-BIS) is typically specified to be around 30 cm.
Maintaining a minimum gap between items is essential for the X-ray machine to produce clear, distinct images of each item. If items are too close or overlapping, their images can merge, making it difficult or impossible for the screener to accurately analyze the contents and detect potential threats.
Operational guidelines for X-ray screening equipment emphasize proper placement of items on the belt, including adequate separation, to maximize screening efficiency and effectiveness. While a larger gap might provide clearer separation, 30 cm is often considered a balance between image clarity and processing speed.