What principle states that the intensity of the radiation is inversely proportional to the square of the distance?

The principle that states the intensity of radiation is inversely proportional to the square of the distance is known as the Inverse Square Law. This law is fundamental in radiology and radiation safety because it helps to understand how radiation exposure decreases with increasing distance from the source of radiation.

When the distance from the source of radiation doubles, the intensity of the radiation becomes one-fourth (1/2² = 1/4) of what it was at the original distance. This principle emphasizes the importance of maintaining an appropriate distance from the radiation source to minimize exposure risks. Understanding the Inverse Square Law is crucial in various medical and dental applications where radiation is used, as it directly impacts safety protocols and practices.

The other options do not accurately describe this relationship and do not reflect the established scientific principle that governs radiation intensity in relation to distance. The Inverse Square Law is widely recognized and used in the field to ensure safe practices in radiation use.