In as resonance -column experiment, a long tube, open at the top, is clamped vertically. By a separate device, water level inside the tube can be moved up or done. The section of the tube from the open end to thewater level acts as a cloed organ pipe. A vibrating tuning fork is held above the open end, and the water level is gradually pushed down. The first and the second resonance occur when the water level is `24.1cm` and `74.1cm` respectively below the open end. The diameter of the tube is `2cm`
A. `2cm`
B. `3cm`
C. `4cm`
D. `5cm`
