A hollow metal sphere of mass \(M\) and volume \(V\) is completely submerged and held in place in a tank of liquid with unknown density \(\rho\). The sphere is tethered to the bottom of the tank by two identical, ideal springs, each with a spring constant \(k\). In the equilibrium position shown, each spring is stretched by a length \(\Delta L\) from its natural length and makes an angle \(\theta\) with the vertical. Which of the following is a correct expression for the density \(\rho\) of the liquid?