A girl inflates a party balloon by blowing air into it, then knots it to keep the air trapped inside. She places the sealed balloon above a hot convector heater. She notices that the balloon’s volume rises greatly. Which statement explains the reason for this increase in volume?
- AThe air in the balloon contracts.
- BThe air in the balloon expands.
- CThe material of the balloon contracts.
- DThe material of the balloon expands.