human
Question: The noble gases, helium, neon, argon, krypton, xenon, and radon, rarely react with other elements because they

Choices:
A) are low-density gases.
B) are not abundant on Earth.
C) have complete outermost energy levels.
D) have two electrons in their outermost energy level.
gpt
The correct answer is 2: have complete outermost energy levels..