This imaging tool measures a magnetic shift to generate an image. a) mri machine b) ultrasound machine c) ct scanner d) pet scanner

I want say it is b ultrasound machine 

hope this helped:)

Ibelieve it's choice d.

If it's a smaller child or infant, place one on the middle of the chest and on the child's back. (if it is a bigger child with enough room for two, place one on the upper right/your left of the chest, and one on the lower left/your right) the pads should never touch each other.