I see why you had difficulty deciding between D and E. At first, they both seem to be clear violations of the given principle. However, E does not involve an impending policy, which is the subject of the principle. An investigation is not the same thing as a policy, so the principle does not apply to answer choice E. When you are able to narrow the choices down to two, make sure you pay close attention to the specific wording of these choices. A tax on luxury cars is a policy, but an investigation isn't. This is why D is correct.