The correct option is D 6
We know the relation between maximum value of pressure in the medium and displacement of the particles in the medium is given by,
Po=BAok
where,
Po is maximum pressure in the medium, B is bulk modulus of medium, Ao is maximum displacement of particles in the medium and k is wave number of sound wave.
⇒Po=2πBAoλ
⇒Ao=Poλ2πB .............(1)
If pressure amplitude is tripled and wavelength is doubled then,
⇒A′o=3Po×2λ2πB
⇒A′o=6Poλ2πB=6Ao [from (1)]