Hey there!
Your answer is "In this brief fraction of a moment they take the first step toward performing a metamorphosis that changes people from a group into a mob."
Foreshadowing is a literary element that writers use to give a sign about a future event that may occur. Therefore, this is the correct answer, because it tells about a future event or gives a sign about.
Have a super awesome day! :)
Brainstorm and get some ideas then write it look for small mistakes when u finish writing or let someone else judge it to is good