Answer:
tense
Step-by-step explanation:
"Loud" is impossible because it states at the start of the passage, "...everybody had gathered around and quieted down..."
"Chaotic" isn't right, either, because it wasn't loud with a bunch of scuffling or partying. Everyone had collected themselves.
"Calm" might work, but seeing as we don't know what's going to happen yet, not really. They might've taken John hostage or they were throwing a surprise party for him.
The best adjective is "tense", seeing as there's suspense in the air.
Hope this helps! :D