A and c.
sound travels faster in steel than in air.
amplitude of sound in the rail is less than and not larger than that in air. The
amplitude of vibrations of particles in steel will be very less, as they cannot move freely like air molecules.
sound can travel larger distances in steel, as the elasticity modulus is more and steel is more elastic. loss of energy is less in steel.
quality of sound in steel is of higher quality, as there are interferences in air from various sources and also there is breeze. Also nature of air is dependent on the humidity too.