Which of the following contributes to image quality in radiography?

The aspect of exposure time and focal spot size plays a significant role in determining image quality in radiography. When considering exposure time, it directly impacts the amount of radiation reaching the film or digital receptor. An appropriate exposure time ensures the image is neither underexposed nor overexposed, maintaining the necessary contrast and detail for diagnostic purposes.

Focal spot size, on the other hand, refers to the area of the target from which x-rays are emitted. A smaller focal spot size results in sharper images with finer details because it produces less geometric blur. This is crucial for distinguishing fine anatomical structures in diagnostic imaging.

In combination, these two factors—exposure time and focal spot size—work together to enhance the clarity and quality of the radiographic image, making option B the correct choice. Other options focus on singular elements, neglecting the comprehensive influence of both exposure time and focal spot size on overall image quality.