What best defines an 'element' in audiovisual context?

In the context of audiovisual systems, an 'element' is best defined as a group of pixels conveying an item of information. This definition encapsulates the concept that individual pixels, while they do form visual content, do not convey substantial information on their own. Instead, it is the collective grouping of these pixels that creates meaningful content, such as images or video frames, which communicate specific ideas or messages.

Grouping pixels into a coherent image or visual element allows for effective communication through visual media. This grouping facilitates the viewer's understanding of scenes, objects, or context in a visual representation.

The other options do not encapsulate this broader definition of an 'element.' A single pixel lacks the necessary information component, and a collection of images simply refers to multiple elements without defining their cohesive role as information carriers. An audio-visual effect, while relevant to audiovisual design, does not specifically address the fundamental visual unit or element that conveys information. Thus, defining an element as a group of pixels more accurately reflects its role in the audiovisual landscape.