A solid whose volume does not change with temperature floats in a liquid. For two different temperatures `t_1` and `t_2` of the liqiud, fraction `f_1` and `f_2` of the volume of the solid remain submerged in the liquid. The coefficient of volume expansion of the liquid is equal to

Options

A. `(f_(1)-f_(2))/(f_(2)t_(1)-f_(1)t_(2))`
B. `(f_(1)-f_(2))/(f_(1)t_(1)-f_(2)t_(2))`
C. `(f_(1)+f_(2))/(f_(2)t_(1)+f_(1)t_(2))`
D. `(f_(1)+f_(2))/(f_(1)t_(1)+f_(2)t_(2))`