Which quality assurance test is commonly performed on radiographic equipment?

The correct choice involves testing for proper alignment and calibration of the X-ray tube, which is a critical quality assurance measure in radiographic equipment. This process ensures that the X-ray tube is producing images that accurately reflect the anatomy of the patient being examined. Proper alignment is essential to avoid misinterpretation of images and reduce patient exposure to unnecessary radiation. Calibration ensures that the equipment is functioning within predetermined standards, which affects the quality of the images produced and ultimately impacts diagnostic accuracy.

The other options, while they might have their significance, do not represent core quality assurance tests commonly practiced in radiography. Testing for the presence of X-ray film, while necessary for operation, does not directly assess the performance of the equipment itself. Patient comfort is an important aspect of patient care but is not considered a direct quality assurance test relating to the equipment's functionality. Lastly, testing for the variety of imaging scans does not evaluate the precision and reliability of the equipment, which is the primary purpose of quality assurance in a radiographic context.