human
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?

Choices:
A) Each balloon behaved differently.
B) Helium gas has a lower density than air.
C) Carbon dioxide causes a balloon to expand.
D) Balloons can be filled with different gases.
gpt
The correct answer is 1: Helium gas has a lower density than air..