"Videos can be difficult to embed in your slides, and so you should give yourself ample time to troubleshoot the process." Why is this statement true?

A. Videos are not made to be played in slides, and so are always difficult to embed.
B. Videos can be difficult to embed in your slides because of their size.
C. Videos are difficult to embed in your slides because they require you to write small amounts of computer code.
D. Not all websites allow their videos to be embedded easily, and so it can take extra time to figure it out.