Which of the following best describes progressive scanning?

A.
combining video from multiple sources into a single image

B.
combining video from a single source taken at two different times into a single image

C.
displaying an entire video image in a single scan

D.
combining two digital signals and alternating between them

Explanation:
Progressive scanning displays the entire video image in a single scan. Although a progressive-scan image is
cleaner than an interlaced image, it requires more bandwidth for the same amount of video, as both odd- and
even-numbered rows of pixels are transmitted and displayed.
Interlacing, or interleaving, is best described as combining video from a single source taken at two different
times into a single image. Interlacing splits a video frame into two sets of pixels, one with even-numbered rows
and one with odd-numbered rows. One set of rows is combined with the opposite set of rows from the next
sequential frame, thereby doubling the perceived frame rate for the same amount of bandwidth. Interlacing is
also described as combining two digital signals, such as audio and video or two separate frames of video, and
alternating between them.
Compositing is best described as combining video from multiple sources into a single image. Basic compositing
can be as simple as overlaying text onto an image. More complex compositing is achieved through the use of
green screen or blue screen technology, in which images are displayed on green or blue areas.

Webopedia: progressive scan