The correct answer is D. Tightly packed particles in solids slow down the light waves; however, sound waves make particles bounce into each other, so they travel faster in solids.
Step-by-step explanation:
The experiment compares the speed of light and sound in different mediums (gas, liquid, and solid). The charts show sound travels faster in a solid medium (ice) than in liquids or gases as the speed in ice was 3200 m/s, while in the liquid was 1500 m/s and in the gas was 346 m/s. Thus, sound waves travel faster in solids, which occurs because for sound to travel particles need to bounce or vibrate, which occurs faster in solids as particles are packed together.
On the other hand, the data about light shows this travels faster in gases (air) because in this medium the speed of light is
, while in a solid the speed is
. This shows opposite to sound, light travels faster in gases, and therefore, the tightly packed particles of soil only slow down light waves.