Explanation:

• The sound wave is a longitudinal mechanical wave.
• The audible sound wave has the frequency of 20 Hz -20000 Hz whereas infrasonic waves have the frequency less than 20 Hz. 
• The ultrasonic waves have a frequency of more than 20000 Hz. 
• Longitudinal waves are such that the displacement of the medium is in the direction of the propagation of the wave. E.g. sound wave, seismic P-Wave etc. 
• A mechanical wave is such that it can transfer energy through a medium only. E.g. Jump rope waves, water waves etc. 

So, only statement I is correct.