Answer: like a school of fish
Explanation:
4 because it doesn't relate to the other 3 answers
This line is foreshadowing because it implies that anything -- even people -- that becomes a burden can easily be destroyed.
Later, when Beatty himself becomes a problem, Montag burns Beatty to death. When Montag killed Beatty, he destroyed the responsibility he owed him. In this way, this line is an element of foreshadowing.
The verbal irony is the fact that you wouldn't actually be happy about the air conditioner breaking, but it highlights the tragedy of the situation