Given scene/plot descriptions from movies or TV shows, and given a specific question about the scene, summarize the question into a title

Q: As we all know, the most exciting part of seeing a movie is the trailers of upcoming movies before the actual film (note, this is coming from an American point of view, I am uncertain if this occurs in theatres everywhere).  However, there doesn't seem to be much of a forethought given to what trailers are shown, besides making sure big movie trailers are shown before other big movies. For instance, the idea of seeing a Dark Knight Rises trailer before Avengers (two different production companies, let alone two rival comic book companies) doesn't seem to make much sense to me.  Is there a strict guideline trailers are released controlled by the MPAA or do the theatres have free run of what to show?

A: What factors go into determining what trailers are played before movies?
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Q: In Mission: Impossible - Fallout (2018), Ethan Hunt's team already strap a tracker block on Lane's neck which makes the tracker device to show "no signal".    Why did Hunt's team set a 90 seconds limit to take out the tracker from Lane's neck?

A: Why did Hunt's team set a 90 seconds limit to take out the tracker from Lane's neck?
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Q: In Game Of Thrones Season 4, the wildling Craster leaves his sons, from his wives (at the same time his daughters), into the woods to be taken by the White Walkers' king, after that he turned them into new White Walkers. I tried to figure out the reason behind this event, but no clues.  So, What is the story behind this action? And why does the White Walkers' king need those new born babies?

A:
Why does Craster give those sacrifices to the White Walkers?
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