Question

What 4 nations lived in harmony until the fire nation attacked

A Earth
B Water
C Air
D Fire

Answer 1

All of the above.

Step-by-step explanation:

Korra ended the Avatar Cycle.

Btw, all four nations lived in harmony, but Sozen said, "LEEEEEEEEEEEEEEEEEEEEETS BURN THE AMAZON!"

Answer 2

you mean 3 and the answer is earth water and air'

Step-by-step explanation: