What can be known about X is that X is a medium of propagation of wave.
Option B is correct
Generally, Waves are defined simply as the propagation of disturbances from one place to another through a medium , Examples of waves is: a swell of the hand.
In conclusion, The information we can decipher about X is that it is a medium, because waves can not travel if there is no medium to travel through.
Read more about Wave
https://brainly.com/question/3004869