hey user!
your answer is here..
correct option is A. steel
we know that sounds travel faster in solid as compared to gas and liquids. in gas the molecules are very loosely packed and there is lot of space between so it takes more time to pass sound from each other. and in liquid, the molecules are closer as compared to gas hence it will be little faster and in solid, the molecules are very tightly packed so it will be the fastest. and among these options, steel is the only solid so the speed of sound in steel will be the fastest.
and note that the closer the molecules are to each other ( tightly packed ) makes the bond also tighter and less time to pass sound.
cheers!!
