A projectile is launched from level ground at time \(t = 0\) with an initial speed \(v_0\) at an angle \(\theta\) above the horizontal. The projectile reaches its maximum height above the ground at time \(t_{max}\). Which of the following pairs of expressions represents the horizontal displacement, \(x\), and vertical displacement, \(y\), of the projectile from its launch point at time \(t = 0.5 t_{max}\)?