In Adobe Premiere Pro, what is meant by the term 'frame size'?

The term 'frame size' in Adobe Premiere Pro refers to the resolution of the video clip. This encompasses the dimensions of the video represented in pixels, such as 1920x1080 for full HD or 3840x2160 for 4K resolution. Understanding frame size is crucial in video editing as it affects the quality of the output video and how it fits in various formats for distribution. A proper frame size ensures that the video playback maintains its intended clarity and visual detail across different devices.

In contrast, the other options address different aspects of video editing and production. The length of the completed film pertains to the duration of the video, which is a separate consideration from resolution. The audio quality relates to sound aspects such as bitrate and sample rate, which do not affect the visual component defined by frame size. Lastly, transitions are visual effects used to switch between different clips or scenes, affecting the flow of the video rather than its fundamental resolution. Thus, the definition of 'frame size' is accurately captured by its association with video resolution.