Iwill mark brainliest when traveling from a solid to air, what would you expect a sound wave to do? stay the same speed fluctuate speed speed up slow down

Good question, when sound waves fly through the air the waves/particles are strongest at the source of the sound (Say you're playing music from your computer when you're next to your computer the music will be louder than it would be 5 feet away)

From this example and fact, you can narrow down your answer and figure out that the sounds do not speed up nor does it stay the same.  

Now the sound would not fluctuate speed because if this was true then when standing right next to your computer you'd notice that sometimes your song would be quiet other times it would be louder (No specified song.  Don't ask me if a specific song can change that... No, that's about the song not the frequency of sound through the air.) 

So your final answer would be, D.  Slow down.