Final answer:
The most important factor in decreasing X-ray exposure to a patient is to limit the time of exposure. Shielding and increasing the distance from the source of radiation are also important.
Step-by-step explanation:
The most important factor in decreasing X-ray exposure to a patient is to limit the time of exposure. The longer a person is exposed to X-rays, the higher the dose they receive. Additionally, shielding is important in absorbing radiation and can be provided by materials like lead aprons and lead-lined doors. Lastly, increasing the distance from the source of radiation helps to spread out the radiation and reduces the dose received by the patient.