In interlaced video, what is the sequence of lines refreshed to the screen?

In interlaced video, the refreshing of lines occurs in a specific manner that is essential for displaying images smoothly and effectively on screens. The process involves scanning the even-numbered lines first, followed by the odd-numbered lines. This method helps to create the illusion of a full image while reducing flicker and improving the perceived frame rate.

When the even scanlines are displayed first, they fill in the image with half of the lines, giving the viewer a clearer picture temporarily. Following this, the odd scanlines are refreshed, completing the full frame. This interlacing technique is beneficial in television broadcasting and some video standards, as it allows for the transmission of images at a lower bandwidth while maintaining visual quality.

The other options describe different scanning methods that do not apply to interlaced video. For instance, refreshing all lines at once characterizes progressive scanning, while the alternating approach mentioned in another option does not align with the interlaced format's methodology. Thus, the correct sequence reflects the fundamental operation of interlaced video, focusing on the proper order of even then odd scanline refreshment.