Option 1 -> Ice-cold water is a liquid where sound travels at approximately 1,400 m/s due to closely packed molecules.
Option 2 -> Air is a gas with widely spaced molecules, where sound travels at approximately 343 m/s (even slower in cold conditions).
Option 3 -> Steel is a solid with tightly packed particles, where sound travels at approximately 5,960 m/s.
Option 4 -> Glass is a solid where sound travels at approximately 4,540 m/s due to dense molecular structure.
Hence, Option 2: Air -> Sound travels slowest in gases because their molecules are far apart compared to liquids and solids, making it harder for sound waves to propagate through particle collisions. The speed increases through liquids and is fastest in solids. -> correct