4. A flash of lightning and the corresponding thunderclap were detected 4 seconds apart. It is
calculated that they took place about 1200 meters away. On what assumption is the
calculation based?

Choices:

A. Light travels almost instantaneously; sound travels at 331 m/s

B. Sound travels instantaneously, light travels at 331 m/s

C. Sound travels at 331 m/s faster than light

D. Light travels 331 m/s faster than sound​