Radiology Practice Test

A barrier should be placed wherever the operator touches in order to prevent any potential contamination or transmission of germs or infections. Options A and B are incorrect because they do not address the main concern of preventing transmission through contact. Option D is incorrect because it does not specify where on the floor the barrier should be placed, and could still potentially allow for transmission through touch. Placing the barrier inside the mouth would not only be impractical, but also potentially dangerous. Therefore, the best option is C, placing the barrier wherever the operator touches.