equations for a the tangent plane and b the normal line at the point Po 1 1 0 on the surface x y z 2 Which equation describes the tangent plane OA x y z 2 0 OB x y z 2 0 OC x y z 2 0 OD x y z 2 0 b Select the equations for the normal line OA x 1 t y 1 t z t OC x 1 t y 1 t z t OB x 1 t y 1 t z t OD x 1 t y 1 t z t