Which of the following describes tissue that appears light grey on a radiograph?

The correct choice illustrates the concept of radiopacity in radiographic imaging. Tissue that appears light grey on a radiograph typically indicates that it has a higher density or mineral content, primarily due to the presence of elements such as calcium. This higher density obstructs the passage of X-rays, leading to reduced X-ray penetration and thus a lighter appearance on the film, known as radiopaque. Examples of radiopaque tissues include dense structures like enamel, dentin, and certain types of bone.

On the other hand, radiolucent areas would appear darker on a radiograph. These areas allow X-rays to pass through more easily, indicating lower density tissues or pathological changes. The choices of transparent and translucent do not pertain to the context of radiographic terms. Transparent would imply complete clarity and lack of obstruction to visibility, while translucent refers to partially allowing light to pass through without providing clear images, which is not applicable in the context of dental radiography.