A 2-column table with 4 rows.

The first column labeled "Elevation (meters)" has entries:
- 500
- 1000
- 1500
- 2000

The second column labeled "Temperature of air (degrees Celsius)" has entries:
- 11.8
- 8.5
- 5.3
- 2.0

As elevation increases, temperature decreases.

At which elevation will sound travel fastest?
A. 500 meters
B. 1000 meters
C. 1500 meters
D. 2000 meters