(c) The explanation of the statements are given below
(i) In meled’s experiment p$\sqrt{T}$=constant.
$\Longrightarrow p^{2}T$=constant
Hence, this statement is correct.
(ii) In Kundt’s experiment distance between two heaps of powder is$\lambda/2$.
Hence, this statement is correct
(iii) Quink’s tube experiment is related with interface.
So, this statement is correct
(iv) Echo phenomena are related with reflection of sound.
So, this statement is correct