A source of sound is in the shape of a long narrow cylinder radiating sound waves normal to the axis of the cylinder. Two points P and Q are at perpendicular distances of 9 m and 25 m from the axis. The ratio of the amplitudes of the waves at P and Q is :-
A. `5:3`
B. `sqrt(5):sqrt(3)`
C. `3:5`
D. `25:9`