If a truck weighs 18,000 n and it’s tires are inflated to a pressure of 190 kpa how large is the area of the trucks tires that are in contact with the ground

Sounds propagates through some kind of medium. usually it's air, but it goes just as well through solid objects like walls, windows etc. a soundwave will compress the (air)molecules in front of it, and if this increased density wave hits your ears, you register it as sound. solid objects like walls are a lot denser than air, this means that they will damp a wave, but also carry it easier.

'b ' is the correct conclusion.