The torque `vec tau` on a body about a given point is found to be equal to `vec A xx vec L` where `vec A` is a constant vector and `vec L` is the angular momentum of the body about the point. From this its follows that -

Options

A. `doversetrarrL` is perpendicular to `oversetrarrL` at all instants of time
B. the component of `oversetrarrL` in the direction of `oversetrarrA` does not change with time
C. the magnitude of L does not change with time
D. all the above