A bob of mass $m$ attached to an inextensible string of length $l$ is suspended from a vertical support. The bob rotates in a horizontal circle with an angular speed $\omega\; rad/s$ about the vertical. About the point of suspension

Question

$\begin{array}{1 1}(A)\;\text{angular momentum changes in direction but not in magnitude} \\ (B)\;\text{angular momentum changes both in direction and magnitude} \\(C)\;\text{angular momentum is conserved} \\(D)\;\text{angular momentum changes in magnitude but not in direction} \end{array} $