142. Subject to the provisions of this Constitution, the executive power of each State shall extend-
(a) To the matters with respect to which the Legislature of the State has power to make laws, and
(b) To the exercise of such rights, authority and jurisdiction as are exercisable under any agreement entered into with any State or group of States for the time being specified in Part III of the First Schedule under article 236 or article 237 of this Constitution.