Each balloon behaved differently. Helium gas has a lower density than air. Carbon dioxide causes a balloon to expand. Balloons can be filled with different gases.
I am hesitating between 4 options to answer the following question, which option should I choose?
Question: A science teacher filled one balloon with helium gas and a second balloon with carbon dioxide. The helium-filled balloon rose to the ceiling, and the balloon filled with carbon dioxide fell to the floor. Which statement is an inference based on this demonstration?
Possibilities:
- Each balloon behaved differently.
- Helium gas has a lower density than air.
- Carbon dioxide causes a balloon to expand.
- Balloons can be filled with different gases.

Helium gas has a lower density than air.