Let the acute angle bisector of the two planes \( x - 2y - 2z + 1 = 0 \) and \( 2x - 3y - 6z + 1 = 0 \) be the plane P. Then which of the following points lies on P?
\( (0, 2, -4) \)
\( (4, 0, -2) \)
\( (-2, 0, -\tfrac{1}{2}) \)
\( (3, 1, -\tfrac{1}{2}) \)