Which of the following options shows sounds with decreasing shrillness?

The Pitch or shrillness of sound is determined by the frequency of the sound. Some examples of high-shrill or pitch sounds are crying babies, shoe squeaking, dogs barking, etc. The more the frequency the more shrill or pitch. 

Therefore the correct decreasing order of shrillness will be$25kHz>4kHz >450Hz>30Hz$

Where,  $25kHz = 25000Hz and 4kHz = 4000Hz$