A small sphere of mass \(m\) is attached to the end of a light string and suspended from the ceiling. The sphere is set into motion so that it travels at a constant speed along a horizontal circular path, causing the string to sweep out a cone. The string makes a constant angle \(\theta\) with the vertical. Which of the following is a correct expression for the magnitude of the tension force \(F_T\) exerted by the string on the sphere?