C

The graph of height (h) versus time (t) for a projectile follows a parabolic shape. This is due to the quadratic nature of the height equation in projectile motion, which can be expressed as:
$$h(t) = v_0 t - \frac{1}{2} g t^2$$
where $v_0$ is the initial velocity and $g$ is the acceleration due to gravity.
Initially, the height increases, reaches a maximum (the vertex of the parabola), and then decreases as the projectile descends. This behavior is best represented by Option C, which shows a curve peaking at a maximum value. Options A, B, and D do not accurately represent this parabolic relationship.