<prompt> The operator should stand at a distance of ___ whiletaking X-ray.6 feet8 feet10 feet2 meters  <response>: Means for Reducing X-Ray Exposure: Use selection criteria to assist in determining type and frequency of radiographic examinations. Use EF-speed film or digital sensors. Use holders to support film or digital sensors intraorally.Make exposures with 60 to 70 kVp. Replace short pointed aiming tubes with open-ended aiming cylinders. Use rectangular collimation for periapical and bitewing images. Use thyroid collars. Stand at least 6 feet 2 m away from patient and away from the X-ray machine preferably out of X-ray room when making exposure. With film, use time-temperature film processing rather than sight processing, or use an automatic processor. Use rare-earth screens for panoramic and cephalometric film imaging or use digital systems. Reduce cone-beam CT beam field of view to region of interest. Reference: White and Pharoahs Oral Radiology Principles and Interpretation 7th edition page no 33 