A stone in hung in air from a wire which is stretched over a sonometer . The bridges of the sonometer are `40 cm` apart when the wire is in unison with a tuning fork of frequency `256 Hz`. When the stone is completely immersed in water , the length between the bridges is `22 cm` for re - establishing unison . The specific gravity of the material of the stone is
A. `((40)^(2))/((40)^(2)+(22)^(2))`
B. `((40)^(2))/((40)^(2)-(22)^(2))`
C. `((40)^(2)+(22)^(2))/((40)^(2))`
D. `((40)^(2)-(22)^(2))/((40)^(2))`