In which one among the following is the speed of sound maximum?

The speed of sound depends primarily on the medium: it is slowest in gases, faster in liquids, and fastest in solids. Official material states sound travels about 330 m/s in air and about 1500 m/s in water, and that solids transmit sound faster than liquids or gases [1]. Textbooks likewise note the ordering gas < liquid < solid for acoustic speeds [2]. While the speed in air increases with temperature (so air at 100°C is faster than at 0°C) this change is small compared to the jump from air to water or wood [3]. Therefore, among the given options the speed of sound is maximum in wood (a solid).

Sources

1. [1] https://gml.noaa.gov/outreach/info_activities/pdfs/MAA_using_sound_waves_to_study_climate_change.pdf
2. [2] https://www.schoolnet.org.za/PILAfrica/en/webs/19537/physics4.html
3. [3] Physical Geography by PMF IAS, Manjunath Thamminidi, PMF IAS (1st ed.) > Chapter 20: Earths Atmosphere > 20.2. Structure of The Earth's Atmosphere > p. 274