Consider the following statements about and passing through a gas.
A. the pressure of the gas at a point oscillates with time.
B. The position of a small layer of the gas oscillates with time.
A. Both `(i)` and `(ii)` are correct.
B. `i` is correct but `(ii)` is wrong
C. `(ii)` is correct but `(i)` is wrong
D. Both `(i)` and `(ii)` are wrong
