Answer:
Joyous
Step-by-step explanation:
Obviously if school was canceled, the students would be joyous.
They might be thankful, yes, but will most likely have more joy than gratitude because they are high schoolers who are probably not as focused on showing gratitude, but more on the fact that there is no school.
They are probably not really "active," which makes it sound like they are running laps because they are so happy.
And if they are erupting, that would make it sound like they are mad, like they are erupting with anger.
So joyous makes the most since.