A particle is projected at point A from an inclination plane with inclination angle `theta` as shown in figure. The magnitude of projection velocity is `vecu` and its direction is perpendicular to the plane. After some time it passes from point B which is in the same horizontal level of A, with velocity `vecv`. Then the angle between `vecu and vecv` will be
A. `theta`
B. `2 theta`
C. `pi-2 theta`
D. `90+ theta`
